RSBO v.10 n.3

v. 10 – n. 3 – July/September 2013

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ISSN: Electronic version: 1984-5685

RSBO

Joinville – SC

v. 10

n. 3

96 p.

2013

Rector Sandra Aparecida Furlan Vice-Rector Alexandre Cidral Dean for Education Sirlei de Souza Dean for Research and Post-Graduation Denise A. Kasper Silva Dean for Extension and Community Affairs Cleiton Vaz Dean for Administration Raul Landmann Editorial Production Editora UNIVILLE Luciana Lourenço Ribeiro Vitor – Text revision and translation e-mail: llribeiro_3@hotmail.com Pricila Ferreira – Administrative assistant Raphael Schmitz – Graphic design Marisa Kanzler Aguayo – Diagramming EDITORIAL BOARD Editor-in-chief Flares Baratto-Filho – Univille and UP, Brazil Administration Editors Fabricio Scaini – Univille, Brazil Luiz Carlos Machado Miguel – Univille, Brazil Associate Editors Edson Alves de Campos – Unesp, Brazil Sandra Rivera Fidel – Uerj, Brazil Gisele Maria Correr Nolasco – UP, Brazil Luiz Fernando Fariniuk – PUC/PR, Brazil Kathleen Neiva – University of Florida, USA Claudia Brizuela – University of Andes, Chile Johannes Ebert – University of Erlangen, Germany Nicolas Castrillon – University São Francisco of Quito, Ecuador Carla Castiglia Gonzaga – UP, Brazil Tatiana Miranda Deliberador – UP, Brazil Denise Piotto Leonardi – UP, Brazil Allan Fernando Giovanini – UP, Brazil

Editorial Board Alessandro Leite Cavalcanti – UEPB, Brazil Carlos Estrela – UFG, Brazil Christoph Kaaden – University of Munich, Germany Fernanda Pappen – UFPel, Brazil Fernando Branco Barletta – Ulbra, Brazil Fernando Goldberg – University of Salvador, Argentine Frank Lippert – Indiana University, USA Guilherme Carpena Lopes – UFSC, Brazil Jesus Djalma Pécora – Forp/USP, Brazil José Antônio Poli de Figueiredo – PUC/RS, Brazil José Carlos Laborde – Catholic University of Uruguay, Uruguay José Luiz Lage-Marques – USP, Brazil José Mondelli – FOB/USP, Brazil Juan Carlos Pontons-Melo – Sao Marcos University, Peru Lourenço Correr Sobrinho – FOP/Unicamp, Brazil Lúcia Helena Cevidanes – University of North Carolyn at Chapel Hill, USA Luciana Shaddox – University of Florida, USA Luis Sensi – University of Florida, USA Luiz Narciso Baratieri – UFSC, Brazil Manoel Damião Sousa-Neto – Forp/USP, Brazil Marco C. Bottino – Indiana University, USA M a r í a Merc e de s A z uer – Javer i a n a Un i versit y, Colombia Mário Tanomaru Filho – Unesp, Brazil Miguel González Rodríguez – Odonthos Institute, Dominican Republic Mu ha nad Hat a m leh – Un iversit y of Ma nchester, England Osmir Batista de Oliveira Júnior – Unesp, Brazil Pedro Bullon Fernandez – University of Sevilha, Spain Regina M. Puppin-Rontani – FOP/Unicamp, Brazil Richard L. Gregory – Indiana University, USA Rivail Antônio Sérgio Fidel – Uerj, Brazil Rodrigo Neiva – University of Florida, USA Sandra Milena Brinez Rodriguez – Javeriana University, Colombia Saulo Geraldeli – University of Florida, USA Ulrich Lohbauer – University of Erlangen, Germany Valentina Ulver de Beluatti – University of Maimonides, Argentine Valeria Gordan – University of Florida, USA Yara Teresinha Corrêa Silva Sousa – Unaerp, Brazil

The content of the articles is of sole responsibility of the authors.

Table of contents Guest editorial................................................................................................................................. 203

Original Research Articles Oral hygiene practices among paramedical staff of a private dental institution in India.................... 205 Amith Holenarasipur Vasanthakumar, Audrey Madonna D’Cruz, Shahima Samad, Shanima, Shazmi Hasan Dhinda, Sheikh Mohammad Mansib, Shreya Nayak

Ethanol is inefficient to remove endodontic sealer residues of dentinal surface................................. 211 Keli Regina Victorino, Edson Alves de Campos, Marcus Vinicius Reis Só, Milton Carlos Kuga, Norberto Batista Faria-Junior, Katia Cristina Keine, Fábio Augusto de Santi Alvarenga

Effect of water storage and hydrophobic adhesive layer application on the bond strength of all-in-one adhesives...................................................................................................................... 217

Gustavo Costa Prevedello, Adilson Yoshio Furuse, Gisele Maria Correr, Regina Maria Helen-Cot Marcos, Denise Piotto Leonardi, Carla Castiglia Gonzaga, Enio Marcos da Silva

Analysis of apical fitting of .06 and .02 tapered gutta-percha master cones in root canals shaped with ProTaper rotary system................................................................................................. 224

Manoel Eduardo de Lima Machado, Cleber Keiti Nabeshima, Guilherme Henrique Rosa Martins, Maria Leticia Borges Britto

Clinical effectiveness of light-curing units of the School of Dentistry of the Federal University of Goias..... 228 Laís Santos Gonçalves, Mércia Bráulio Gonçalves, Marília Morais Martins, Gersinei Carlos de Freitas, Lawrence Gonzaga Lopes, Terezinha Jesus Esteves Barata

Effect of Gates Glidden, La Axxess, SX and ultrasound on the circularity and area of mesial canals of mandibular molars................................................................................................. 234

Etevaldo Matos Maia Filho, Erick Miranda Souza, Edimar Oliveira Meneses, Cláudia de Castro Rizzi

Influence of different surface treatments on the shear bond strength of a methacrylate resin composite repaired with silorane-based resin................................................................................... 240 Leonardo Fernandes da Cunha, Bruno Moreno Nascimento, Samantha Shaffer Pugsley Baratto, Carla Castiglia Gonzaga, Adilson Yoshio Furuse, José Mondelli, Odirlei Arruda Malaspina

DMFT index of 12 year-old students of public schools participating in the Project of Education for Working for Health......................................................................................................245

Denise Vizzotto, Helena Maria Antunes Paiano, Ana Caroline Rudey, Andréia Karina Lovera, Pricylla Hagemann, Tatiane Gazolla

Ligature-induced periodontitis associated to alcohol using and stress on animal’s behavior: study in rats.................................................................................................................................... 252 Tereza Aparecida Delle Vedove Semenoff, Álvaro Henrique Borges, Alessandra Nogueira Porto, Fabio Luis Miranda Pedro, Igor Francisco Arruda de Abreu, Natalino Francisco da Silva, Alex Semenoff Segundo

Evaluation of the effectiveness of manual and rotary techniques in the desobturation and reinstrumentation of root canal....................................................................................................... 257 Érica Pozo Mautone, Elias Pandonor Motcy de Oliveira, Simone Viegas da Silva Bonatto, Tiago André Fontoura de Melo

Burnout syndrome: evaluation in dentists in the city of Fortaleza, Brazil.......................................... 266 Sandro Dias Rocha Mendes Carneiro, Camila Castro Tourinho, Tathiane Araújo Pedrosa do Vale, Yvonne de Souza Gurjão Campêlo, Fábio de Almeida Gomes, Danilo Lopes Ferreira Lima

Literature Review Article Cone beam computed tomography and applicability in Dentistry – literature review........................ 272 Fabiana Caroline da Silva, Ilana Sanamaika Queiroga Bezerra, Nelson Luis Barbosa Rebellato, Antonio Adilson Soares de Lima

Case Report Articles Preventive and surgical intervention in patient with cerebral palsy – case report.............................. 278

Gabriella Siqueira da Matta, Maurício Barriviera, Andréia de Aquino Marsiglio, Cláudia Maria de Souza Peruchi, Alexandre Franco Miranda

Surgical treatment of transmigration of mandibular canine ............................................................. 284 Ana Maria Estivalete Marchionatti, Vinícius Felipe Wandscher, Felipe Wehner Flores, Jorge Abel Flores

Pleomorphic adenoma in the oral mucosa of a young adult: a case report........................................ 289 Juliana Andrade Cardoso, Carla Martins Ferreira, Mariana Moura de Jesus Fernandes Guerra, Gleicy Gabriela Vitória Spinola Carneiro Falcão, Lívia Souza Pugliese, Jener Gonçalves de Farias

Guest editorial Overreliance on P-value interpretation in dental scientific reports Unquestionably, statistics is regarded as the fundamental part of the vast majority of scientific reports in various medical fields. It is the basic tool used to differentiate materials, procedures and techniques subjected to countless modalities of scientific evaluations. It is unusual to read a scientific report in the medical or dental fields without a statistical description of the behavior of the variables under test. Most of those studies, when not relying sole in descriptive statistics, use the P-value as the cut-off point in which a decision to accept or not the previously set null hypothesis can be made, based on the so-called statistical significance. This is rather largely considered a sound way to interpret the raw data and provide unbiased conclusions regarding the performance of the groups under test [4].

Nevertheless, a P-value interpretation may be of little or no clinical significance [1, 5, 6]. For instance, a 10-day difference in the duration of an orthodontic treatment between two techniques may imply in statistical significance, but certainly has no clinical relevance. However, the given P-value-based results are usually explored by the authors in such a (statistical) manner that influences clinicians’ decision-make for treatment A or B. This attitude could lead a given treatment to be prematurely abandoned or to suffer from a severe reduction in interest by the scientific community. In fact, the sole P-value interpretation might be an inefficient method to drive the data analysis towards the conclusions, especially when dependent variables of clinical impact are under analysis. In such cases, the inclusion of Confidence Intervals (CI’s) would be of great importance to highlight how the variation for both groups is highly coincident [1, 5, 6]. This can give more precise information on how these results shall impact in the clinical reality.

In biology, assumed a sample size of enough power has been selected, it is unusual that two given conditions are really equal. Therefore, there is a real probability that a difference is found while comparing biological events [1]. However, this statistical find, may be of neglect or very little clinical importance. Thus, many studies may result in a treatment to be rejected by clinicians based on the statistical results only. The scientific community should carefully rethink this attitude.

In the dental field, several typically studied variables are very prone to drive people into limited interpretations, as long as P-values are the sole-performed evaluation. Some remarkable examples are leakage data, materials penetration into tubules, time required to finish a dental movement, push-out strength, teeth resistance to fracture, instruments resistance to torsion, etc... Here, a perceived statistical significant difference between materials usually results in material’s rejection or lower acceptance in daily practice, especially if new, untested materials are on the focus. A simple observation of P-value difference, innumerous times, hide a neglectable clinical difference.

For instance, if a restoration A de-adheres from the tooth at 250N which is statistically different from restoration B at 260N, it must be questioned whether this 10N has any impact on the clinical use of restoration B, specially if those mean values are above the range of chewing forces. The report of 95% CI’s would help authors to demonstrate that the interval of variance between the materials is not in a range of clinical importance, although null hypothesis has been rejected [5, 6].

I strongly believe that it is time for Peer-Reviewed Journals to increase attention on drawing more strict guidelines on how to report and interpret statistical data. Establishing more specific rules for statistical reports is a current tendency by some dental journals [2, 3], but indubitably much more should be done in this direction, such as, for instance, the set of an editorial board exclusively to deal with statistics of manuscripts. While we wait for this movement to increase, I believe that raw data table and CI’s are to be required routinely from any accepted study, especially those when clinical parameters are the dependent variables. A very simple way to comprise with CI’s description is to include diagram bars. Discussion and conclusions should also be drawn from this data interpretation.

This obviously might result in more space to be required for a single manuscript, and more accurate review from the Editorial team. However, for the sake of knowledge, would help to keep dental science in a taught-rising direction.

References 1. Dancey CP, Reiddy J. Estatística sem matemática para psicologia. Tradução de Lorí Viali. Porte Alegre: Artmed; 2006. 608 p.

2. De-Deus G. Research that matters – root canal filling and leakage studies. Int Endod J. 2012 Dec;45(12):1063-4.

3. Fouad AF. Journal of endodontics: new guidelines, new directions. ���������������������������� J Endod. 2013 Feb;39(2):159.

4. ��������������������������������������������������������������������������������������������������������� Krithikadatta J, Valarmathi SJ. Research methodology in dentistry: part II – the relevance of statistics in research. Conserv Dent. 2012 Jul;15(3):206-13.

5. Lucena C, Lopez JM, Pulgar R, Abalos C, Valderrama MJ. ������������������������������������������ Potential errors and misuse of statistics in studies on leakage in endodontics. Int Endod J. 2012 Jul;24.

6. Polychronopoulou A, Pandis N, Eliades T. Appropriateness of reporting statistical results in orthodontics: the dominance of P values over confidence intervals. Eur J Orthod. 2011 Feb;33(1):22-5.

Erick Souza DDS, MSc, PhD in Endodontics Professor of Florence Institute, São Luís, MA, Brazil

ISSN: Electronic version: 1984-5685 RSBO. 2013 Jul-Sep;10(3):205-10

Original Research Article

Oral hygiene practices among paramedical staff of a private dental institution in India Amith Holenarasipur Vasanthakumar1 Audrey Madonna D’Cruz2 Shahima Samad3 Shanima3 Shazmi Hasan Dhinda3 Sheikh Mohammad Mansib3 Shreya Nayak3 Corresponding author: Amith H. V. Department of Public Health Dentistry People’s College of Dental Sciences and Research Centre, People’s University Bhanpur – Bhopal – Madhya Pradesh – India E-mail: amith_hv@yahoo.co.in Department of Public Health Dentistry, People’s College of Dental Sciences and Research Centre, People’s University – Bhopal – Madhya Pradesh – India.

2 Department of Public Health Dentistry, A. B. Shetty Memorial Institute of Dental Sciences, Nitte University – Mangalore – Karnataka – India.

3 Undergraduate students, ����������������������������������������������������������������������������������������������������� A. B. Shetty Memorial Institute of Dental Sciences, Nitte University – Mangalore – Karnataka – India.

1

Received for publication: December 17, 2012. Accepted for publication: April 8, 2013.

Keywords: dental plaque; oral health; tooth brushing.

Abstract Introduction: Health promotion in dentistry is targeted at the two most common oral diseases – dental caries and periodontal disease.

The maintenance of good oral hygiene is considered to be a central issue in oral health promotion. Objective: To assess the oral hygiene practices among paramedical staff of a private dental institution in India. Material and methods: A cross sectional questionnaire survey was undertaken among 100 paramedical staff of a private dental institution in Mangalore, India. Data was collected by using self designed questionnaire. Results: About 49% of the subjects brushed thrice with soft toothbrush and 55% changed their tooth brush once in 3 months. About 77% of them cleaned their tongue either by tongue cleaner, toothbrush or finger and 82% of the subjects used tooth paste.

About 56% of the subjects had never used dental floss. Majority of the subjects (56%) visited the dentist only when required. Conclusion: Oral hygiene practices among the paramedical staff were poor.

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Introduction

Survey instrument

Health behavior is defined as “the activities undertaken by people in order to protect, promote or maintain health and to prevent disease” [10].

The broad categories of factors that may influence individual and community health behavior include: knowledge, beliefs, values, attitudes, skills, finance, materials, time and the influence of family members, friends, co-workers, opinion leaders and even health workers themselves [8]. Health promotion in dentistry is targeted at the two most common oral diseases – dental caries and periodontal disease [1]. The maintenance of good oral hygiene is considered to be a central issue in oral health promotion. The cornerstone of prevention of the two major oral diseases, dental caries and periodontal disease, is the maintenance of a clean mouth or a clean tooth surface [3]. A clean tooth surface is one which is free from dental plaque. The people who have assimilated the knowledge and feel a sense of personal control over their oral health are more likely to adopt self-care behaviour [1]. Good oral hygiene and a positive attitude towards maintaining it, reflects individual’s health, confidence, life style and personality also [11]. Habits like cleaning of teeth, use of mouth rinse, use of tobacco and smoking affect the oral hygiene and oral health [11].

Paramedical staff such as receptionists, nurses, technicians, attenders forms an important group in a dental institution. They play a role of linking between patients and doctors in the hospital. It is therefore important that auxiliary staff caring for people in hospitals themselves have a core of knowledge of their oral care needs. They are also expected to maintain their oral hygiene. There is scarce published literature on assessment of oral hygiene practices of paramedical staff in India.

Hence, this study aimed to assess the oral hygiene practices among paramedical staff of a private dental institution in India. The null hypothesis for the present study was that the oral hygiene practices among the paramedical staff were poor.

A self designed, close ended questionnaire was developed in English language. Each questionnaire contained two parts: the first part dealt with basic demographic details of the participants, the second part dealt with the questions regarding practice of oral hygiene.

Material and methods A cross sectional questionnaire survey was undertaken among the paramedical staff of A. B. Shetty Memorial Institute of Dental Sciences, Nitte University, Mangalore, India during the period August-September 2011. The study protocol was reviewed and ethical approval was obtained by the Institutional ethical committee (ABSM/ EC/25/2011).

Questionnaire reliability A pilot study was conducted on 10% of the total sample size i.e. 10 paramedical staff in order to check the feasibility of the study and to check the adequacy of the questions [12]. Based on the results of the pilot study, the questionnaire was revised and modified. Questionnaire showed high degree (0.91) of agreement during test-retest of questionnaire. Those individuals who participated in the pilot study were not considered for the main study to prevent possible bias.

Study sample There are 125 paramedical staff (receptionists, nurses, technicians, attenders) working in A. B. Shetty Memorial Institute of Dental Sciences, Mangalore, India. Subjects who were not present during three consecutive visits were excluded from the study. The purpose of the study was explained to each participant and informed consent was obtained from each participant who was willing to participate in the study. Participation was voluntary, and all the participants were queried anonymously. The questionnaires were collected in person immediately after completion.

Statistical analysis A score of ‘1’ for each correct answer and ‘0’ for every wrong answer was given. The scores for all the 10 questions were added together to obtain an “oral hygiene practice score” for each individual. Overall mean oral hygiene practice score was calculated by dividing the total oral hygiene practice scores of all individuals by the number of individuals.

Comparison of mean scores between the genders was done using Unpaired t test. The participants were categorized into three categories based on their age as 34years and below, 35 – 44 years and 45years and above. Comparison of mean oral hygiene practice scores of the three age groups was executed using One-way ANOVA. The years of experience was categorized into 9 years and below, 10-20 years and

207 - RSBO. 2013 Jul-Sep;10(3):205-10 Amith et al. – ����������������������� Oral hygiene practices among ������������������������������������� paramedical staff of a private dental ���������������������� institution in India �����

21 years and above. Comparison of mean oral hygiene practice scores across the years of experience was done using One-way ANOVA. Comparison of mean scores across four qualification groups (7th standard, 10th standard, 12th standard and nursing) was performed using One-way ANOVA. The level of significance was set at 5% and probability value of <0.05 was considered as statistically significant. The data were tabulated and analyzed using SPSS 16.0 version (SPSS Inc., Chicago, IL, USA).

Results The present study was carried out to assess the oral hygiene practices of paramedical staff of a private dental institution in Mangalore, India. Of the 125 paramedical staff, 100 participated in the survey. The response rate was 80%. Table I shows the sociodemographic characteristics of the study participants’. The study group consisted of 70 females and 30 males with a mean age of 39.25 years and having a mean experience of 14.25 years.

Table I – Sociodemographic characteristics of the participants

Number (%)

Mean age (years)

Mean years of experience

Males

30 (30)

40.2

15.2

Females

70 (70)

38.3

13.3

Total

100 (100)

39.25

14.25

Table II shows the responses of the study participants to the questions asked regarding their oral hygiene practices. It was noted that about 49% of the subjects brushed thrice with soft toothbrush.

Around 34% of them brushed their teeth using both horizontal and vertical strokes. About 55% of them cleaned their tongue by tongue cleaner and 18% used a toothbrush for tongue cleaning. However, 23% never cleaned their tongue. About 55% changed their tooth brush once in 3 months. Majority of the participants’ (82%) used tooth paste along with the toothbrush for brushing their teeth. However, only 14% selected the toothpaste because of its fluoride content. Most of them selected the toothpaste based on the attractiveness of the product. About 56% of the participants’ brushed their teeth for about 2-5 minutes. When enquired about flossing, 40% of the subjects’ flossed occasionally and 56% of them had never used dental floss. Only 20% of the subjects visited a dentist every 6 months. Majority of the subjects (56%) visited the dentist only when required and 8% had never visited a dentist.

Table II – Responses of participants to the questions

a] once daily b] twice daily How many times do c] thrice daily you brush daily? d] after every meal

What type of toothbrush do you use for brushing?

Number

%

2

2

39

39

49

49

10

10

e] I never brush

0

0

a] hard

0

0

b] medium

41

41

c] soft

49

49

d] ultra soft

10

10

19

19

19

19

28

28

34

34

a] horizontal strokes Which among the b] vertical strokes following brushing techniques do you c] circular strokes use while brushing? d] both horizontal and vertical strokes

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Table II (continued)

a] tongue cleaner b] tooth brush c] finger d] do not clean my tongue a] once in three months How often do you b] once in six mouths change your tooth c] every year brush? d] when the bristles are frayed a] tooth paste Which among the b] tooth powder following do you use along with your c] charcoal tooth brush? d] other specify a] fluoride containing b] depending on the pleasantness of the taste How do you select of the tooth paste your tooth paste? c] based on the cost d] based on the attractiveness of the product a] once daily b] twice daily How often do you floss? c] occasionally d] do not use dental floss a] less than 1 minute For how long do you b] for 1 minute brush your teeth? c] for 2-5 minutes a] every six months b] once in a year How often do you visit your dentist? c] only when required d] never visit the dentist

Which among the following do you use to clean your tongue?

Number

%

55 18 4 23 55 19 5 21 82 11 6 1 14

55 18 4 23 55 19 5 21 82 11 6 1 14

29

29

21 36 4 0 40 56 24 20 56 20 16 56 8

21 36 4 0 40 56 24 20 56 20 16 56 8

Table III shows the mean practice score across genders. The overall mean of oral hygiene practice score was 4.07±1.48. The mean score for males was 1.3±2.58 and that for females was 3.96±2.03. Unpaired t test shows that the difference in mean scores across genders was statistically significant (p < 0.05).

Table III – Comparison of mean oral hygiene practice scores between genders using Unpaired t test

Gender

Mean score (SD)

Male

1.3 (2.58)

Female

3.96 (2.03)

T

Df

Standard error of difference

p value

5.5230

98

0.482

0.0001*

* p < 0.05, significant

Table IV shows the mean oral hygiene practice score across age, educational qualification and years of experience. The mean scores of participants 34yrs and below, 35-44yrs and 45yrs and above of age were 4.2±1.76, 3.76±1.85 and 6.44±3.31 respectively. The difference in mean scores across various age groups was statistically significant using One-way ANOVA test (p < 0.05, significant). The study

209 - RSBO. 2013 Jul-Sep;10(3):205-10 Amith et al. – ����������������������� Oral hygiene practices among ������������������������������������� paramedical staff of a private dental ���������������������� institution in India �����

participants having an experience of 9yrs and below had a mean score of 4.0±1.18, those of 10-20 yrs experience had a mean score of 4.01±1.87 and those 21 years and above had a mean score of 5.0±2.40; the difference of which was not statistically significant (p > 0.05).

Based on their educational qualification, those who had studied up to 7th standard, 10th standard, th 12 standard and nursing education had a mean score of 3.87±0.3, 4.0±2.30, 4.44±1.25 and 4.5±0.24 respectively. Although there was a marginal increase in the mean practice scores with an increase in the educational qualification, the difference was not statistically significant (p < 0.05) (table IV).

Table IV – Comparison of mean oral hygiene practice scores across age, years of experience and educational qualification using One way ANOVA

N

Mean score (SD)

Sum of squares

df

Mean square

34 yrs and below

15

4.2 (1.76)

Between: 58.108

2

29.054

35-44 yrs

76

3.76 (1.85)

Within: 387.703

97

3.997

45 yrs and above

9

6.44 (3.31)

Total: 445.811

99

9 yrs and below

5

4.0v (1.18)

Between: 5.534

2

2.767

10-20 yrs

89

4.01 (1.87)

Within: 342.097

97

3.527

21yrs and above

6

5.0 (2.40)

Total: 347.631

99

7th std

11

3.87 (0.3)

Between: 4.863

3

1.621

10

std

58

4.00 (2.30)

Within: 343.228

96

3.575

std

27

4.44 (1.25)

Nursing

4

4.5 (0.24)

Total: 348.091

99

Variable

Age

Years of experience

Educational qualification

th

12

th

F

p value

7.269

0.001*

0.785

0.459, NS

0.453

0.715, NS

* p < 0.05, significant NS – not significant

The results of the present study reveal that oral hygiene practices among the paramedical staff were poor and hence the null hypothesis was accepted.

Discussion Oral health care is considered as of primary importance in general health care [11]. The effective tooth cleaning practices are indicative of positive oral health behavior whereas frequent consumption of sugary foods represents negative health behavior (risk behavior) [9]. Regular removal of dentogingival plaque is crucial for the maintenance of oral health, free from dental caries and periodontal disease [4]. Although the mechanical cleaning is useful in controlling supragingival plaque, it depends on person’s capabilities to maintain a good standard [2, 5]. For a motivated, wellinstructed person with time and skill, mechanical

plaque-control measures are sufficient to attain complete dental health [2]. A number of factors have been suggested as playing a role in motivation of people in performing oral hygiene procedures [5]. Most important amongst these factors are self recognition of the disease and the knowledge of various preventive measures [5].

Paramedical staff in a dental college forms an important part of the dental team. Their role is essential in maintaining asepsis, maintaining records, fi xing appointments, delivering oral hygiene inst ruct ions etc. Hence, assessment of t heir ora l hyg iene pract ices too becomes important.

The results of the present study revealed that all of them were performing tooth brushing on a daily basis. This was similar to the findings of Kaira et al. [7] where all the nursing students performed tooth brushing. About 82% of the participants in the present study were using toothpaste. This was higher to that reported by

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Kaira et al. [7] where 70% of nursing students used toothpaste. In the present study, although 82% of them were using toothpaste, only 14% of them were aware that they need to select toothpaste based on whether it contains fluoride or not. Most of them selected and purchased the toothpaste based on the attractiveness of the product. It is quite surprising that in spite of working in a dental college and with the availability of free dental services, 8% of the paramedical staff had never consulted a dentist. These results show the gap in oral health knowledge among this particular population. The findings of this study were similar to study conducted in Mississippi in which knowledge of dental health was lacking among the nursing staff of nursing homes [6].

When compared gender wise, females had a better oral hygiene practice score (3.96±2.03) than males (1.3±2.58). This may be due to the fact that females are generally more hygiene conscious than males [10].

The results of this study must be interpreted in the context of potential methodological limitations.

Since this survey was self-reported data, there exists a tendency of respondents to provide socially acceptable answers. However, such surveys maybe helpful in planning oral health education programs for the paramedical staff. It is recommended that oral health education programs be conducted regularly in the dental colleges to improve the oral hygiene knowledge and practices among this particular group.

3. D’Cruz AM, Shankar Aradhya MR. Impact of oral health education on oral hygiene knowledge, practices, plaque control and gingival health of 13- to 15-year-old school children in Bangalore city. Int J Dent Hygiene. 2012.

Conclusion

10. Sharda AJ, Shetty S. A comparative study of oral health knowledge, attitude and behaviour of non-medical, para-medical and medical students in Udaipur city, Rajasthan, India. Int J Dent Hygiene. 2010;8:101-9.

T he or a l hy g ie ne pr a c t ic e s a mon g t he paramedical staff of A. B. Shetty Memorial Institute of Dental Sciences were poor.

4. Haas AN, Reis A, Lemos Jr. CA, Pannuti CM, Escobar E, Almeida ER et al. ���������������������� Daily biofilm control and oral health: an epidemiological challenge consensus – Brazilian advisory panel in oral health. Braz J Periodontol. 2012;22(3):40-6.

5. Hebbal M, Ankola AV, Vadavi D, Patel K. Evaluation of knowledge and plaque scores in school children before and after health education.

Dent Res J. 2011;8:189-96.

6. Howard RM. Survey of oral hygiene knowledge and practice among Mississippi nursing home staff [cited 2013 Mar 16]. Available from: URL: http://udini.proquest.com/view/survey-of-oralhygiene-knowledge-goid:868355421/.

7. Kaira LS, Srivastava V, Giri P, Chopra D. Oral health related knowledge, attitude and practice among nursing students of Rohilkhand Medical college and hospital: a questionnaire study. J Orofac Res. 2012;2(1):20-3.

8. Park K. Park’s textbook of preventive and social medicine. 18th ed. Banarsidas Bhanot Publishers; 2005.

9. Pine CM, Harris R. Community oral health. 2 nd ed. Quintessence Book Publishing Co.; 2007.

1. Brukiene V, Aleksejuniene J. An overview of oral health promotion in adolescents. Int J Paed Dent. 2009;19:163-71.

11. US Department of Health and Human Services.

Oral health in America: a report of the surgeon general – executive summary. Rockville, MD: US Department of Health and Human Services, National Institute of Dental and Craniofacial Research, National Institutes of Health; 2000.

2. Claydon CN. Current concepts in toothbrushing and interdental cleaning. Periodontol 2000.

2008;48:10-22.

12. WHO. Health research methodology. A guide for training in research methods. 2 nd ed. World Health Organization; 2001.

References

ISSN: Electronic version: 1984-5685 RSBO. 2013 Jul-Sep;10(3):211-6

Original Research Article

Ethanol is inefficient to remove endodontic sealer residues of dentinal surface Keli Regina Victorino1 Edson Alves de Campos1 Marcus Vinicius Reis Só1 Milton Carlos Kuga1 Norberto Batista Faria-Junior1 Katia Cristina Keine1 Fábio Augusto de Santi Alvarenga1 Corresponding author: Milton Carlos Kuga Avenida Saul Silveira, 5-01 CEP 17018-260 – Bauru – SP – Brasil E-mail: kuga@foar.unesp.br 1

Araraquara Dental School – Araraquara – SP – Brazil.

Received for publication: February 28, 2013. Accepted for publication: April 22, 2013.

Keywords: endodontics; image analysis; SEM; surface analysis.

Abstract Introduction: Endodontic sealer residues on dentinal surface have negative effects on adhesion of adhesives system and/or can cause discoloration of the dental crown. Objective: To evaluate the efficacy of 95% ethanol in removal of residues of epoxy-based (AH Plus), methacrylate-based (Epiphany SE) or calcium-based (Sealapex) sealers on dentinal surface. Material and methods: Thirty-two bovine incisor dental crown fragments (0.5 mm x 0.5 mm) were treated with 17% EDTA and 2.5% NaOCl. The specimens were divided into three experimental groups (n = 10): G1 (AH Plus), G2 (Epiphany SE) and G3 (Sealapex). In each group was applied a coating of one endodontic sealer type and were left undisturbed for 5 minutes. After this period, the specimens were cleaned with 95% ethanol. The control group was composed by two specimens that did not receive any sealer or cleaning treatment. The sealer residues persistence after cleaning with 95% ethanol was evaluated by scanning electron microscopy (x500) and a score system was

212 – RSBO. 2013 Jul-Sep;10(3):211-6 Victorino� et al. – Ethanol ��������������������������������������������������������������� is inefficient to remove endodontic sealer residues of dentinal ���������������� surface

applied. Data obtained were analyzed by Kruskal-Wallis and Dunn tests (α = 5%). Results: Moderate amount of endodontic sealer residues were observed in all groups, regardless of the endodontic sealer compositions. G1, G2 and G3 presented similar amount of sealer residues on dentinal surface after cleaning with 95% ethanol (p > 0.05). Conclusion: 95% ethanol was inefficiency to remove completely AH Plus, Epiphany SE and Sealapex residues of sealercontaminated dentin.

Introduction An essential procedure of the endodontic treatment is to provide a complete obturation of root canal and to develop an adequate fluidtight seal mainly at the apical third [2]. Actually, different sealers have been proposed, mainly containing calcium, methacrylate or epoxy resin in their compositions [6, 21, 24].

Sealapex (SybronEndo, Romulus, MI, USA) is a ca lcium-based sea ler, composed of t wo pastes: a catalyzer paste (isobut yl salicylate resin, silicon dioxide, bismuth trioxide, titanium dioxide pigment) and a base paste (N-ethyltoluene sulfonamide resin, silicon dioxide, zinc oxide, and calcium oxide). This sealer has acceptable biological compatibility, but may lead to slight crown discoloration over time [4, 8].

AH Plus (Dentsply De Trey, Konstanz, Germany) is an epoxy-based cement, also composed ���������������� of two pastes: paste A (bisphenol-A epoxy resin, bisphenolF epox y resi n, ca lciu m t ugst ate, zi rconiu m ox ide, sí l ica a nd i ron ox ide pi g ment s) a nd paste B (dibenzyldiamine, aminoadamantane, t r icyclodec a ne - d i a m i ne, c a lciu n t u n g st ate, zirconium oxide, silica, and silicone oil). This material is routinely used as gold standard material for testing endodontic sealer [1]. Notwithstanding, the persistence of this sealer on pulp chamber dentine reduces the microtensile bond of selfetching adhesives [22�� ].

Following recent advances in adhesives systems, methacrylate-based resin sealers were developed to be used in radicular obturation. Epiphany (Pentron Clinical Technologies, Wallingford, CT) was the first methacrylate-based sealer used in endodontics. This sealer is basically composed by resins (Bis-GMA, UDMA, PEGDMA, EBADMA), fillers (barium sulphate, bismuth oxychloride, calcium hydroxide, silica, and silane-treated barium-aluminosilicate glass), colouring pigment,

dual-cured initiators (cumene hydroperoxide, thiosinamine, champhorquinone), and stabilizer (butylated hydroxytoluene [2,6-di-tert-butyl-4methylephenol]) [11]. In first generation, this system had a core material (Resilon), a dual-curing resinbased sealer (Epiphany) and a self-etching primer [21]. In second generation, Epiphany self-etch (SE) system has only two components: Epiphany selfadhesive sealer (Epiphany SE; Parkell, Farmigton, NY, USA) and Resilon. Acid resin monomers that are originally found in SE primers have been incorporated into the self-adhesive resin-based sealers, reducing the application time and the possibility of errors during adhesive procedures [12]. The system has possible capability to create a “monoblock” between the radicular dentin wall and root canal obturation [12].

Presence of residues of endodontic materials interferes in the prognosis of the endodontic treatment [13, 19]. Presence of endodontic sealer residues on the pulp chamber dentin may cause crown discoloration and/or negatively affect the bond strength of dentin adhesives [4, 20, 22].

To prevent these adverse effects, an appropriate cleaning of the pulp chamber dentin should be carried out. Several solutions containing ethanol, ethyl acetate and acetone have been recommended for removal of debris and residues from the dentin surface [23]. Ethanol is one of the most recommended cleaning substances to dentin cleaning after root canal obturation [14].

However, there are no studies that assessment its effectiveness to remove endodontic sealer residues of different chemical composition.

The aim of this study was to evaluate the efficacy of 95% ethanol on the removal of residues of epoxy-based (AH Plus), methacrylate-based (Epiphany SE) or calcium-based (Sealapex) sealers on dentinal surface crown of bovine teeth.

213 – RSBO. 2013 Jul-Sep;10(3):211-6 Victorino� et al. – ��������������������������������������������������������������� Ethanol is inefficient to remove endodontic sealer residues of ���������������� dentinal surface

Material and methods

SEM evaluation

Thirty-two freshly extracted bovine permanent incisors, stored into a solution of 0.1% thymol at 4°C were used. Thirty-two tooth fragments with flat dentin surfaces, measuring 0.5 cm x 0.5 cm, were obtained from the buccal surface of dental crowns using a slow-speed Isomet precision saw (Buehler Ltd, Lake Bluff, IL, USA) under water irrigation.

Next, 17% EDTA (Biodinâmica Ind. Com, Ibiporã, PR, Brazil) was applied onto the dentin surfaces for 3 minutes. Specimens were then washed with 2.5ml of 2.5% NaOCl (Asfer, São Caetano do Sul, SP, Brazil) and dried with an air stream.

The specimens (n = 10, each group) received a layer of: G1 – AH Plus sealer (Dentsply, DeTrey, Germany), G2 – Epiphany SE (Pentron Clinical Technologies, Wallingford, CT) or G3 – Sealapex (SybronEndo, Romulus, MI, USA) which was spread evenly over the dentin surface with a microbrush (Microbrush Int., Grafton, WI, USA) and left undisturbed for 5 minutes. The sealers were mixed and handled according to manufacturer recommendations. Following, the dentine surfaces were wiped using cotton pellets saturated with 95% ethanol (Rinse-N-Dry, Racine, MI, USA), until the surface appears visibly clean. After this step, no additional rinsing was performed.

Control specimens (n = 2) did not receive sealer application. All specimens were prepared by the same operator.

For SEM analysis, the specimens were dried at room temperature for 7 days, dehydrated in silica for 24 h, mounted onto aluminum stubs with silver paint, sputter-coated with gold, and examined under a DSM 940A scanning electron microscope (Carl Zeiss, Oberkochen, BadenWurttemberg, Germany) operating at 15 kV. Each fragment was initially visualized at x100, and for assessment of the amount of sealer residues, further observations under x500 were conducted in 4 different fields. A representative image of each specimen at x500 was used for evaluation.

Evaluation of the amount of sealer residues onto the dentine surface was carried out by attributing scores, as follows: Score 1 – no smear layer and all the tubules opened; Score 2 – minimum amount of smear layer and >50% of the dentine surface clean; Score 3 – moderate amount of smear layer and <50% of the dentine surface clean; Score 4 – heavy smear layer with almost all tubules obstructed [17]. SEM evaluations were performed by two examiners who were blind to the experimental groups. The examiners were initially calibrated using the reference SEM images. The scores were compared, and when a difference was found, the evaluators together examined the sample. Data were submitted to Kruskal-Wallis and Dunn tests, at 5% significance level.

Results The 95% ethanol did not provide the complete removal of endodontic sealer residues on dentinal surface. The residues persistence was similar and there is no statistical difference among experimental groups (p > 0.05). In all specimens were observed a moderate amount of endodontic sealer residues coating the dentinal surface. Table I shows the frequency of scores assigned, mean and median scores in the experimental groups, regarding the presence of residues on dentin. SEM images representative of control group and experimental groups (G1, G2 and G3) are shown in figure 1. In control specimens, dentinal tubules were visible and dentinal surface without debris.

Table I – Frequency of scores assigned, mean and median scores in the experimental groups, regarding the presence of residues on dentin

G1 – AH Plus

G2 – Epiphany SE

G3 – Sealapex

Score 1

0

0

2

Score 2

4

3

0

Score 3

5

6

6

Score 4

1

1

2

Mean scores

2.6

2.5

2.2

Median

2.5

2

2

214 – RSBO. 2013 Jul-Sep;10(3):211-6 Victorino� et al. – ��������������������������������������������������������������� Ethanol is inefficient to remove endodontic sealer residues of ���������������� dentinal surface

Figure 1 – SEM micrographs (500X) representative of control and experimental groups: control (A), G1 – AH Plus sealer residues (B), G2 – Epiphany SE sealer residues (C), and G3 – Sealapex sealer residues (D)

Discussion Through SEM analysis, was possible to observe that 95% ethanol did not provide the complete removal of residues of epoxy-based (AH Plus), methacrylate-based (Epiphany SE) or calciumbased (Sealapex) sealers of dentinal surface. All specimens showed moderate amount of endodontic sealer residues on bovine dentine crown.

The method used to evaluate the presence of residues was through the analysis of dentine surface using scanning electron microscopy [9, 15]. Flat dentin fragments (0.5 cm x 0.5 cm) from bovine pulp chamber were used as substrate to avoid analysis in curved areas, which could adversely affect in interpretation of the results.

AH Plus sealer contains in its composition two non-polar resins: bisphenol-A and bisphenol-F epoxy resins [7]. The efficacy of a solvent in dissolving a solute or softening a polymer may be explained by the concept that polar solvents are better at dissolving polar compounds [22]. As ethanol is a polar solvent and resins of endodontic sealers are non-polar substances, it could be assumed that ethanol is incompletely miscible with these sealers, resulting in persistence of residues on dentinal surface. This date is in accordance with observed

by Roberts et al. [22].

According to described by the manufacturer, to avoid a quick evaporat ion a nd enable a n adequate time for use, the ethanol used in this study contains a low concentration of water in its composition. This may also have contributed to persistence of residues, because water is immiscible or incompletely miscible with some resin contained into the endodontic sealers [5, 10, 22].

Although all specimens presented residues on dentinal surface, its characteristics were different, as shown in figure 2. To Epiphany SE, the dentinal tubules were totally obliterated by sealer, but on this layer, it had presence of residues that were not totally removed by 95% ethanol. Despite the ethanol is recommended to use in solubility test to methacrylate-based sealer, this substance did not provide adequate ability to removal residues [16]. As Sealapex has a poorly formed matrix with low stability, high water absorption and reasonable degradation of this matrix occurs when in contact with water [3, 18], showing diffuse residues on dentine and with smaller size than those of AH Plus.

Therefore, 95% ethanol used as endodontic sealer residues removal protocol was inefficient, maintaining residues that can have negative effects on the prognosis of endodontic treatment. This led

215 – RSBO. 2013 Jul-Sep;10(3):211-6 Victorino� et al. – ��������������������������������������������������������������� Ethanol is inefficient to remove endodontic sealer residues of ���������������� dentinal surface

to the conclusion that 95% ethanol was inefficiency to completely remove sealer residues on dentinal surface. Further studies should be undertaken in order to develop more efficacious cleaning protocols for the removal of endodontic sealers residues on dentinal surface, avoiding negative effects on bond strength of adhesive system or coronal discoloration of endodontically-treated teeth.

Conclusion Through the methodology used in this study, it was possible to observe that 95% ethanol was inefficiency to provide the complete removal of residues of epoxy-based (AH Plus), methacrylatebased (Epiphany SE) or calcium-based (Sealapex) sealers on dentinal crow n surface of bovine teeth.

References 1. Assmann E, Scarparo RK, Böttcher DE, Grecca FS. Dentin ��������������������������������������������� bond strength of two mineral trioxide aggregate-based and one epoxy resin-based sealers.

J Endod. 2012 Feb;38(2):219-21.

2. Branstetter J, Von Fraunhofer JA. The physical properties and sealing action of endodontic sealer cements: a review of the literature. J Endod. 1982 Jul;8(7):312-6.

3. Caicedo R, Von Fraunhofer JA. The properties of endodontic sealer cements. J Endod. 1988 Nov;14(11):527-34.

4. Davis MC, Walton RE, Rivera EM. Sealer distribution in coronal dentin. J Endod. 2002 Jun;28(6):464-6.

5. Donnelly A, Sword J, Nishitani Y, Yoshiyama M, Agee K, Tay FR et al. Water sorption and solubility of methacrylate resin-based root canal sealers. J Endod. 2007 Aug;33(8):990-4.

6. Duarte MAH, Demarchi ACCO, Giaxa MH, Kuga MC, Fraga SC, Souza LCD. Evaluation of pH and calcium ion release of three root canal sealers. J Endod. 2000 Jul;26(7):389-90.

7. Goswami DN, Jha PC, Mahato K. Shellac as filler in sheet molding compound. Ind J Chem Tech.

2004 Jan;11(1):67-73.

8. Hollan������������������������������� d R, Souza V, Nery MJ, Bernabé ����� PFE, Otoboni-Filho JA, Dezan-Junior E et al. �������� Calcium salts deposition in rat connective tissue after the implantation of calcium hydroxide containing sealers. J Endod. 2002 Mar;28(3):173-6.

9. Hülsmann M, Rümmelin C, Schäfers F. Root canal cleanliness after preparation with different endodontic handpieces and hand instruments: a comparative SEM investigation. J Endod. 1997 May;23(5):301-6.

10. Kaplan AE, Goldberg F, Artaza LP, De Silvio A, Macchi RL. ������������������������������������� Disintegration of endodontic cements in water. J Endod. 1997 Jul;23(7):439-41.

11. Karapınar-KazandaĞ M, Bayrak OF, Yalvaç ME, Ersev H, Tanalp J, Sahin F et al. Cytotoxicity of 5 endodontic sealers on L929 cell line and human dental pulp cells. Int Endod J. 2011 Jul;44(7):626-34.

12. Kim YK, Grandini S, Ames JM, Gu LS, Kim SK, Pashley DH et al. Critical review on methacrylate resin-based root canal sealers. J Endod. 2010 Mar;36(3):383-99.

13. Kuga MC, Campos EA, Faria-Junior NB, Só MVR, Shinohara AL. Efficacy of NiTi rotary instruments in removing calcium hydroxide dressing residues from root canal walls. Braz Oral Res. 2012 Jan-Feb;26(1):19-23.

14. Kuga MC, Só MVR, Faria-Júnior NB, Keine KC, Faria G, Fabricio S et al. Persistence ������������������������ of resinous cement residues in dentin treated with different chemical removal protocols. ����������������� Microsc Res Tech.

2012 Jul;75(7):982-5.

15. Kuga MC, Só MV, De Campos EA, Faria G, Keine KC, Dantas AA et al. ��������������� Persistence of endodontic methacrylate-based cement residues on dentin adhesive surface treated with different chemical removal protocols. ������������������ Microsc Res Tech.

2012 Oct;75(10):1432-6.

16. Moreira FCL, Antoniosi-Filho NR, Souza JB, Lopes LG. ���������������������������������� Sorption, solubility and residual monomers of a dental adhesive cured by different light-curing units. Braz Dent J. 2010 NovDec;21(5):432-8.

216 – RSBO. 2013 Jul-Sep;10(3):211-6 Victorino� et al. – ��������������������������������������������������������������� Ethanol is inefficient to remove endodontic sealer residues of ���������������� dentinal surface

17. Oliveira ACM, Lima LM, Pizzolitto AC, SantosPinto L. Evaluation of the smear layer and hybrid layer in noncarious and carious dentin prepared by air abrasion system and diamond tips. Microsc Res Tech. 2010 Jun;73(6):597-605.

21. Resende LM, Rached-Junior FJ, Versiani MA, Souza-Gabriel AE, Miranda CE, Silva-Sousa YT et al. A comparative stud��������������������� y of physicochemical properties of AH Plus, Epiphany, and Epiphany SE root canal sealers. Int Endod J. 2009 Sep;42(9):785-93.

18. Ørstavik D, Nordahl I, Tibballs JE. Dimensional change following setting of root canal sealer materials. Dent Mater. 2001 Nov;17(6):512-9.

22. Roberts S, Kim JR, Gu L, Kim YK, Mitchell QM, Pashley DH et al. The efficacy of different sealer removal protocols on bonding of self-etching adhesives to AH Plus-contaminated dentin. J Endod. 2009 Apr;35(4):563-7.

19. Parsons JR, Walton RE, Ricks-Williamson L. In vitro longitudinal assessment of coronal discoloration from endodontic sealers. J Endod.

2001 Nov;27(11):699-702.

20. Plotino G, Buono L, Grande N, Pameijer CH, Somma F. Non vital bleaching: a review of the literature and clinical procedures. �������������� J Endod. 2007 Apr;34(4):394-407.

23. Saraç D, Bulucu B, Saraç S, Kulunk S. The effect of dentin-cleaning agents on resin cement bond strength to dentin. J Am Dent Assoc. 2008 Jun;139(6):751-8.

24. Silva DF, Stang EC, Campos EA, Kuga MC, Faria G, Kuga GK. Interference of the assessment method in pH values of an epoxy-based cement.

RSBO. 2012 Apr-Jun;9(2):133-6.

ISSN: Electronic version: 1984-5685 RSBO. 2013 Jul-Sep;10(3):217-23

Original Research Article

Effect of water storage and hydrophobic adhesive� layer ��������������������������������������� application on the bond strength of all-in-one adhesives Gustavo Costa Prevedello1 Enio Marcos da Silva1 Regina Maria Helen-Cot Marcos1 Denise Piotto Leonardi1 Gisele Maria Correr1 Adilson Yoshio Furuse1 Carla Castiglia Gonzaga1 Corresponding author: Carla Castiglia Gonzaga Universidade Positivo Rua Prof. Pedro Viriato Parigot de Souza, n. 5.300 – Campo Comprido CEP 81280-330 – Curitiba – PR – Brasil E-mail: carlacgonzaga2@gmail.com 1

Master of Science Program in Clinical Dentistry, Positivo University – Curitiba – PR – Brazil.

Received for publication: February 23, 2013. Accepted for publication: April 26, 2013.

Keywords: dentinbonding agents; dental bonding; dentin.

Abstract Introduction: To prevent the rate of water absorption and degradation of exposed collagen and the resin matrix on the hybrid layers, the use of an additional layer of hydrophobic resin on all-in-one adhesives is one of the approaches to improve the bond strength and infiltration of monomers in demineralized dentin. Objectives: To compare the microshear bond strength of different self-etching adhesive systems, and to evaluate the effect of the application of a hydrophobic adhesive layer on all-in-one adhesive systems after a storage period of 48 h and 30 days in distilled water at 37oC. Material and methods: Bovine incisor crowns were polished to expose flat dentin surfaces. The crowns were randomly distributed into 14 groups (n = 12) according to the adhesive system [Clearfil SE Bond (CSEB), AdheSE (ASE), Adper Scotchbond SE (SSE), Adper Easy Bond (EB), and Go! (GO)], and storage time. In two groups (indicated as GO+B and EB+B), a layer of a hydrophobic adhesive was applied on all-in-one adhesive systems. After 48h and 30 days

218 – RSBO. 2013 Jul-Sep;10(3):217-23 Prevedello� et al. – Effect ���������� of water �������������� storage and ���� hydrophobic ������������ ��������������� adhesive������� layer application ������������������� on the bond ����������������� strength of ����������� all-in-one ��������� adhesives

of storage in distilled water at 37oC, microshear bond strength was determined. The data were statistically analyzed by ANOVA and Tukey’s test (α = 5%). Results: After 48h, EB, EB+B, CSEB, and GO+B showed higher bond strength values. The application of a hydrophobic layer did not influence EB and increased GO bond strength values. After 30 days, CSEB, SSE, and EB+B showed the highest bond strength values. Comparing groups of all-in-one adhesives with and without a hydrophobic adhesive-resin layer, the bond strength values showed no significant difference. Conclusion: The application of a hydrophobic adhesive-resin layer increased bond strength values only at 48h. With respect to bond degradation over time, only EB showed a statistically significant decrease of bond strength after 30 days.

Introduction Currently, the etch-and-rinse and self-etching approaches are the two strategies of resin-based adhesive systems to accomplish the bonding to enamel and dentin. Despite the relative ease of application and less-sensitive technique related to the application of simplified self-etching adhesive systems, their bond strength is not yet considered effective in enamel or dentin. Many authors reported lower bond strength values for all-in-one adhesives when compared to two-step self-etching adhesives [2, 3, 19, 26, 29]. Moreover, many problems are associated with their use. These adhesives, even when polymerized to form adequately the hybrid layer, are porous structures that can act as semipermeable membranes, allowing the bi-directional flow of water through the adhesive layer if it is not coated with a hydrophobic adhesive-resin layer [27].

The literature also reported a high amount of nanoleakage when these adhesive systems were used [28] and a greater decrease in bond strength over time when compared with conventional adhesives such as those in which a layer of hydrophobic adhesive-resin was applied [3]. There is also evidence that small nanoscale defects in the adhesive layer seen in nano infiltration tests can act as channels for water passage [28].

The degradation of the hybrid layer may be due to a number of factors. Among these, the most important is the incomplete penetration and infiltration of monomers in the demineralized dentin [13], the heterogeneous distribution of monomers through the hybrid layer,[11] the inadequate or insufficient polymerization [14, 21], and the degradation and hydrolysis of both the resin component and the non-hybridized exposed collagen [5].

Different clinical approaches have been proposed to improve the bond strength and infiltration of

monomers in demineralized dentin in order to reduce the rate of water absorption and degradation of exposed collagen and the resin matrix [5]. Among the most commonly described approaches are the use of an additional layer of hydrophobic resin [23, 24] the application of multiple layers of simplified adhesives,[12, 16] enhanced solvent evaporation [12], increased polymerization time [6], and the use of MMPs (matrix metalloproteinases) inhibitors [7].

The objectives of the present study were to compare the microshear bond strength of different self-etching adhesive systems and to evaluate the effect of the application of a hydrophobic adhesive layer on all-in-one adhesive systems after a storage period of 48 h and 30 days in distilled water at 37oC.

Material and methods B�������������������������������������������������� ovine incisors were selected, cleaned, and stored into 0.5% chloramine T solution, under refrigeration, until the preparation of the specimens. The crowns were separated and their buccal surfaces polished ��������� under constant irrigation����������������������� to expose flat dentin surfaces��.

Each crown was embedded in a PVC cylinder with acrylic resin (Jet, Artigos ������������������������������� Odontológicos Clássico� Ltd, Sao Paulo, Brazil) and randomly divided into 14 groups (n = 12), according to the adhesive system and storage time. A ������������������������������������ standard smear layer was prepared on the dentin surfaces using 600-grit SiC paper for 1 min���������������������������������������������������� under water irrigation. The self-etching adhesives [Clearfil SE Bond (CSEB), AdheSE (ASE), Adper Scotchbond SE (SSE), Adper Easy Bond (EB), and Go! (GO)] ���������������������������������������������� were applied according to each manufacturer’s recommendations. The adhesive systems and their form of application are shown in table I. In two additional groups, all-in-one adhesives received an additional layer of hydrophobic resin (����������� Scotchbond Multi Purpose, 3M ESPE������������������� ) (EB+B and GO+B).

219 – RSBO. 2013 Jul-Sep;10(3):217-23 Prevedello� et al. – ���������� Effect of �������������� water storage ���� and ������������ hydrophobic ��������������� adhesive������� layer application ������������������� on the bond ����������������� strength of ����������� all-in-one ��������� adhesives

Table I – ������������������ Bonding procedure for �������� the adhesive ����������������������������� systems investigated

Type

Code

Adhesive

Clearfil SE Bond CSEB (Kuraray, Osaka, Japan)

Two-step self-etching adhesive

All-in-one self-etching adhesive

Bonding procedure 1.

2.

3.

4.

5.

Apply primer for 20 s Dry with mild air stream Apply bond Dry with gentle air stream Light cure for 10 s

1.

2.

3.

4.

5.

Apply primer for 30 s Gently air dry Apply bond Gently air dry Light cure for 10 s

ASE

AdheSE (Ivoclar Vivadent, Amherst, NY, USA)

SSE

1. Apply liquid A so that a continuous red-colored layer is obtained on the surface Adper Scotchbond SE 2. Apply liquid B into the entire wetted surface of the (Adper SE Plus, 3M bonding area for 20 s. The red color will disappear.

ESPE, St. Paul, MN, 3. Thoroughly air dry for 10 s USA) 4. Apply a second coat of liquid B to the entire surface 5. Lightly air dry for 10s 6. Light cure for 10 s

EB

Adper Easy Bond 1. Apply adhesive for 20 s (Adper Easy One, 3M 2. Gently air dry until liquid does not move anymore ESPE) 3. Light cure for 10 s

GO

Go! (SDI, Victoria, Australia)

B

Hydrophobic adhesive 1. Apply one coat after all-in-one adhesives EO e GO (Scotchbond Multi 2. Light cure for 15 s Purpose – 3M ESPE)

1. Remove excess water 2. Apply adhesive on the surface and leave in place for 20 s 2. Air dry for 5 s leaving a glossy surface 3. Light cure for 10 s

Transparent cylindrical matrixes with an internal diameter of 0.7 mm and height of 1 mm (Tygon tubing R-3603, Saint-Gobain Performance Plastics, Maime Lakes, FL, USA) were positioned onto the dentin surface treated with the described adhesives. A composite resin (shade A2, Amelogen Plus, Ultradent Products Inc., South Jordan, UT USA) was carefully inserted into each matrix and light-cured for 20 s at 1000 mW/cm2 (LED curing Bluephase, Ivoclar Vivadent, Schann, Lietchenstein).

The specimens were stored into distilled water at 37ºC for two different periods: 48 h (early bond strength) and 30 days (delayed bond strength).

The microshear bond strength tests were performed with a universal testing machine ��������� (Kratos, São Paulo, SP, Brazil)�������������������������� at a cross-head speed of 0.5 mm/min until fracture. The specimens were carefully aligned to allow that the load be applied

as close as possible to the bonding interface at the cylinder bases with aid of a stainless steel wire-loop (0.2 mm diameter).

After the microshear bond strength tests, the fractured interfaces were examined in a light microscope at x57 magnification (SZX9, Olympus, Tokyo, Japan) to determine the failure mode, classified as adhesive, cohesive, or mixed.

Data were statistically analyzed using ANOVA and Tukey’s test with a significance level of 5%.

Results The results for the microshear bond strength to dentin determined for the adhesives tested as a function of storage time in distilled water at 37oC are shown in table II.

220 – RSBO. 2013 Jul-Sep;10(3):217-23 Prevedello� et al. – ���������� Effect of �������������� water storage ���� and ������������ hydrophobic ��������������� adhesive������� layer application ������������������� on the bond ����������������� strength of ����������� all-in-one ��������� adhesives

Table II – Means��, standard ��������������������� deviations, and ������������������������������ coefficients of variation for ���� microshear ����������� bond ������������������������������ strength (MPa) to dentin

Microshear bond strength to dentin (MPa)

Group CSEB

48 h

30 days

27.13±6.32 (23%)

28.61±6.15 (21%)a

ab

ASE

14.73±3.81 (26%)e

17.85±3.33 (19%)cde

SSE

21.22±4.72 (22%)bcde

23.48±6.05 (26%)abc

EB

28.70±6.27 (22%)a

20.28±4.74 (23%)cde

EB+B

27.55±6.06 (22%)ab

22.51±4.80 (21%)abcd

GO

15.55±3.71 (24%)de

16.18±3.37 (21%)de

GO+B

23.16±6.68 (29%)abc

17.18±3.76 (22%)cde

Values followed by same superscript letters are statistically similar (p > 0.05)

For the 48 h storage period, EB showed the higher bond strength values, statistically similar to EB+B, CSEB, and GO+B. On the other hand, ASE, GO and SSE showed lower microshear bond strengths. It can also be noted that all-in-one and two-step self-etching adhesives behaved differently.

Regarding the two-step self-etching adhesives, CSEB showed higher bond strength values, while ASE showed lower values. As for the all-in-one adhesives, EB showed the highest bond strengths, while GO presented one of the lowest values. When comparing groups of all-in-one adhesives applied according to manufacturers’ recommendation to those in which a layer of hydrophobic adhesive was applied, the bond strength values did not change or increase.

For the 30-day storage period, CSEB showed the higher bond strength values, statistically similar to those of groups SSE and EB+B. Conversely, GO, GO+B, ASE, EB, and EB+B presented lower microshear bond strength values. Again, for the two-step self-etching adhesives, CSEB demonstrated higher bond strength values, while ASE demonstrated lower values. As for the all-in-one adhesives, EB

Figure 1 – Frequency of failure mode

showed higher bond strength values, while GO presented one of the lowest values. Comparing the groups of all-in-one adhesives applied according to manufacturers’ recommendation to those in which a layer of hydrophobic adhesive was applied, the bond strength values showed no statistically significant difference for both EB and GO. Regarding the bond strength degradation over time, it can be observed that only EB showed a statistically significant decrease in the bond strength values after 30 days of storage in distilled water.

Even if a statistical difference could not be noted for the two other two groups (EB+B and GO+B), a decreasing trend in the bond strength values was observed. On the other hand, it was also possible to notice that some groups (CSEB, ASE, SSE, and GO) presented a tendency towards increasing the bond strength values over time, even though no statistically significant difference was observed.

The results of failure analysis performed after the microshear bond strength tests are shown in figure 1. All groups showed predominantly adhesive and mixed failures. Only SSE after 30 days storage showed cohesive failure in resin (29.2%).

221 – RSBO. 2013 Jul-Sep;10(3):217-23 Prevedello� et al. – ���������� Effect of �������������� water storage ���� and ������������ hydrophobic ��������������� adhesive������� layer application ������������������� on the bond ����������������� strength of ����������� all-in-one ��������� adhesives

Discussion The results of the present study indicated that the all-in-one and two-step self-etching adhesives behaved differently. Other studies obtained similar results, indicating that the all-in-one adhesives presented lower bond st reng t h va lues when compared to two-step self-etching adhesives [2, 3, 26]. One possible explanation for this fact would be that, as all-in-one adhesives can create thin layers [16], their polymerization can be diminished by the presence of oxygen [25].

Clearfil SE Bond showed high bond strength values in various studies and is considered the gold standard when comparing different self-etching adhesive systems [2, 19, 26]. The good performance of this adhesive appears to be related to some factors. Its pH of ≈2.0 allows a lower dissolution of smear plugs while maintaining hydroxyapatite crystals [30] and facilitates the penetration and polymerization of monomers in the underlying dentin to form an adequate hybrid layer. Also, the presence of photoinitiators in both components (acidic primer and adhesive) increases the efficiency of monomer polymerization and facilitates the solvent evaporation [22]. It has also been suggested that the high hydrolytic stability of MDP and its chemical interaction with the dental tissues can contribute to a long-term durability of the bond strength [15].

Also a two-step self-etching adhesive, AdheSE showed lower microshear bond strength values when compared to Clearfil SE Bond. This could be possibly explained because its self-etching capacity is based on the phosphonic acid acrylates. These monomers have a pH of ≈���� ����� 1.4 [1] ���� with ����� greater ����������������� capacity to dissolve the smear layer, smear plugs, and weak bonds to dentin. Their highly hydrophilic properties also contribute to their behavior as a semipermeable membrane,[8] leading to the degradation of the resin-dentin bonds when stored in water [1].

Among the two-step self-etching adhesives, Adper Scotchbond SE is noteworthy. Its composition and especially the fact that aqueous primer alone does not etch the tooth tissues led to controversies regarding the classification of this adhesive, but it can be categorized as a two-step self-etching system since the second application of the adhesive can be considered equivalent to the application of the hydrophobic resin in traditional two-step self-etching adhesives [19].

The results of some in vitro studies indicate that the use of a hydrophobic layer on all-inone adhesives could maintain or improve their

performance [4, 10, 20]. In the present study, corroborating the aforementioned results, the use of an additional layer of hydrophobic resin also indicated good results. Reis et al. [23] showed that the use of a hydrophobic adhesive layer prevented the decrease in bond strength of three all-in-one adhesives after six months of water storage. The use of a hydrophobic resin layer on single-step selfetching adhesives was also tested in a randomized clinical trial of 18 months in non-carious cervical lesions [24]. The results demonstrated that the retention rates of restorations after 18 months were significantly higher for groups in which a layer of hydrophobic adhesive was applied.

There are several possible explanations for this increase in bond strength. This layer of hydrophobic resin seems to limit the diffusion of water through the hybrid layer, which could have happened relatively quickly without the presence of this hydrophobic layer [27], inhibiting polymerization and weakening the adhesive-composite interface.

This additional layer may also have decreased the removal of non-polymerized monomers and oligomers of the hybrid layer. Zones of hydrophilic low-polymerized phases that allow the movement of water have been identified in the hybrid layer of self-etching adhesives [28]. In both cases, this additional hydrophobic layer would enable all-inone adhesives to simulate two-step self-etching adhesives, increasing the thickness of the adhesive layer [4], which could reduce the polymerization stress [9] and improve the stress distribution during the tests. These two factors may have contributed to the higher values of bond strength observed in the groups with the presence of an additional layer of hydrophobic resin.

Consideri ng t he si ng le-step sel f- etch i ng adhesives, the good performance of EB, comparable to CSEB at 48 h with and without the additional layer of hydrophobic adhesive, can be explained by its pH around 2.4, similar to the performance of CSEB (������ ≈����� 2.0).

Another important concern is the degradation of the adhesive layer over time. This degradation is the result of the interaction of polymers with water in dentinal f luid and saliva, which has a plasticizing effect and separates the polymer chains and reduces the mechanical properties of the material [1, 17, 18]. In the present study, after 30 days of storage in distilled water at 37ºC, a decrease of the bond strength values occurred for the adhesives tested. However, only group EB showed a statistically significant decrease. In the EB+B group, with application of a hydrophobic

222 – RSBO. 2013 Jul-Sep;10(3):217-23 Prevedello� et al. – ���������� Effect of �������������� water storage ���� and ������������ hydrophobic ��������������� adhesive������� layer application ������������������� on the bond ����������������� strength of ����������� all-in-one ��������� adhesives

adhesive layer, the bond strength values after 30 days of storage were statistically similar to those for two-step adhesives. This demonstrates that the hydrophobic adhesive layer was effective in decreasing the high permeability attributed to all-in-one adhesives. However, it must be noted that the GO+B group obtained lower values of bond strength. These values were not statistically different from those observed for the group without the hydrophobic adhesive layer.

The performance of the adhesive systems in terms of bond strength changed over time, indicating that the results of bond strength tests in the short term may not accurately reflect their behavior in the long term, in particular for dentin. However, it should be noted that the storage period of 30 days, used in this study, can still be considered short for this type of test and that further studies are needed to evaluate the bond strength of these and other self-etching adhesives systems with longer storage periods.

Conclusion It can be concluded that, ����������������������� for the storage period of 48 h, the application of a hydrophobic adhesive layer on the single-step self-etching adhesives led to an increase in the bond strength values only for GO group, which presented a bond strength value similar to that of CSEB. For the storage time of 30 days, the bond strength values showed no significant difference for both EB and GO when a hydrophobic adhesive layer was applied. ����� With respect to the degradation of strength over time, only EB showed a statistically significant decrease of bond strength after 30 days.

References 1. Abdalla AI. Effect of long-term water aging on microtensile bond strength of self-etch adhesives to dentin. Am J Dent. 2010 Feb;23(1):29-33.

2. Ansari ZJ, Sadr A, Moezizadeh M, Aminian R, Ghasemi A, Shimada Y et al. Effects �������������������� of one-year storage in water on bond strength of self-etching adhesives to enamel and dentin. Dent Mater J. 2008 Mar;27(2):266-72.

3. Armstrong SR, Vargas MA, Fang Q, Laffoon JE. Microtensile bond strength of a total-etch 3-step, total-etch 2-step, self-etch 2-step, and a self-etch 1step dentin bonding system through 15-month water storage. J Adhes Dent. 2003 Spring;5(1):47-56.

4. Brackett WW, Ito S, Tay FR, Haisch LD, Pashley DH. Microtensile dentin bond strength of selfetching resins: effect of a hydrophobic layer. Oper Dent. 2005 Nov-Dec;30(6):733-8.

5. Breschi L, Mazzoni A, Ruggeri A, Cadenaro M, Di Lenarda R, De Stefano et al. Dental adhesion review: aging and stability of the bonded interface.

Dent Mater. 2008 Jan;24(1):90-101.

6. Cadenaro M, Antoniolli F, Sauro S, Tay FR, Di Lenarda R, Prati C et al. Degree ������������������������� of conversion and permeability of dental adhesives. Eur J Oral Sci. 2005 Dec;113(6):525-30.

7. Campos EA, Correr GM, Leonardi DP, BaratoFilho F, Gonzaga CC, Zielak JC. Chlorhexidine �������������� diminishes the loss of bond strength over time under simulated pulpal pressure and thermo-mechanical stressing. J Dent. 2009 Feb;37(2):108-14.

8. Carrilho MR, Carvalho RM, Tay FR, Yiu C, Pashley DH. ��������������������������������� Durability of resin-dentin bonds related to water and oil storage. Am J Dent. 2005 Dec;18(6):315-9.

9. Choi KK, Condon JR, Ferracane JL. The effects of adhesive thickness on polymerization contraction stress of composite. ����������������� J Dent Res. 2000 Mar;79(3):812-7.

10. De Vito Moraes AG, Francci C, Carvalho CN, Soares SP, Braga RR. Microshear ���������������������������� bond strength of self-etching systems associated with a hydrophobic resin layer. J Adhes Dent. 2011 Aug;13(4):341-8.

11. Eliades G, Vougiouklakis G, Palaghias G. Heterogeneous distribution of single-bottle adhesive monomers in the resin-dentin interdiffusion zone.

Dent Mater. 2001 Jul;17(4):277-83.

12. Erhardt MC, Osorio R, Pisani-Proenca J, Aguilera FS, Osorio E, Breschi L et al. ���������� Effect of double layering and prolonged application time on MTBS of water/ethanol-based self-etch adhesives to dentin. Oper Dent. 2009 Sep-Oct;34(5):571-7.

13. Hashimoto M, Ohno H, Endo K, Kaga M, Sano H, Oguchi H. The effect of hybrid layer thickness on bond strength: demineralized dentin zone of the hybrid layer. Dent Mater. 2000 Nov;16(6):406-11.

14. Hass V, Luque-Martinez I, Sabino NB, Loguercio AD, Reis A. Prolonged exposure times of one-step self-etch adhesives on adhesive properties and durability of dentine bonds. J Dent. 2012 Dec;40(12):1090-102.

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15. Inoue S, Koshiro K, Yoshida Y, De Munck J, Nagakane K, Suzuki K et al. Hydrolytic stability of self-etch adhesives bonded to dentin. J Dent Res. 2005 Dec;84(12):1160-4.

16. Ito S, Tay FR, Hashimoto M, Yoshiyama M, Saito T, Brackett WW et al. Effects of multiple coatings of two all-in-one adhesives on dentin bonding. J Adhes Dent. 2005 Summer;7(2):133-41.

17. Lenzi TL, Soares FZ, Rocha RO. Degradation ������������ of resin-dentin bonds of etch-and-rinse adhesive system to primary and permanent teeth. Braz Oral Res. 2012 Dec;26(6):511-5.

18. Loguercio AD, Stanislawczuk R, Mena-Serrano A, Reis A. Effect of 3-year water storage on the performance of one-step self-etch adhesives applied actively on dentine. J Dent. 2011 Aug;39(8):578-87.

19. Mine A, De Munck J, Cardoso MV, Van Landuyt KL, Poitevin A, Kuboki T et al. Bonding effectiveness of two contemporary self-etch adhesives to enamel and dentin. J Dent. 2009 Nov;37(11):872-83.

23. Reis A, Albuquerque M, Pegoraro M, Mattei G, Bauer JR, Grande RH et al. Can ���������������������� the durability of one-step self-etch adhesives be improved by double application or by an extra layer of hydrophobic resin? J Dent. 2008 May;36(5):309-15.

24. Reis A, Leite TM, Matte K, Michels R, Amaral RC, Geraldeli S et al. Improving ����������������������������� clinical retention of one-step self-etching adhesive systems with an additional hydrophobic adhesive layer. J Am Dent Assoc. 2009 Jul;140(7):877-85.

25. Rueggeberg FA, Margeson DH. The effect of oxygen inhibition on an unfilled/filled composite system. J Dent Res. 1990 Oct;69(10):1652-8.

26. Sarr M, Kane AW, Vreven J, Mine A, Van Landuyt KL, Peumans M et al. Microtensile bond strength and interfacial characterization of 11 contemporary adhesives bonded to bur-cut dentin.

Oper Dent. 2010 Jan-Feb;35(1):94-104.

27. Tay FR, Pashley DH, Suh BI, Carvalho RM, Itthagarun A. Single-step adhesives are permeable membranes. J Dent. 2002 Sep-Nov;30(7-8):371-82.

20. Nakaoki Y, Sasakawa W, Horiuchi S, Nagano F, Ikeda T, Tanaka T et al. Effect of double-application of all-in-one adhesives on dentin bonding. J Dent.

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ISSN: Electronic version: 1984-5685 RSBO. 2013 Jul-Sep;10(3):224-7

Original Research Article

Analysis of apical fitting of .06 and .02 tapered gutta-percha master cones in root canals shaped with ProTaper rotary system Manoel Eduardo de Lima Machado1 Cleber Keiti Nabeshima1 Guilherme Henrique Rosa Martins1 Maria Leticia Borges Britto2 Corresponding author: Cleber Keiti Nabeshima Av. Amador Bueno da Veiga, n. 1.340 – Penha CEP 03636-100 – São Paulo – SP – Brasil E-mail: cleberkn@hotmail.com 1 2

Department of Operative Dentistry, School of Dentistry, University of São Paulo – São Paulo – SP – Brazil.

Department of Endodontics, Cruzeiro do Sul University – São Paulo – SP – Brazil.

Received for publication: January 20, 2013. Accepted for publication: February 22, 2013.

Keywords: Endodontics; root canal preparation; gutta-percha.

Abstract Introduction: The fitting of gutta-percha master cone is important for the obturation step. The modified single-cone technique using larger taper has provided better filling of gutta-percha than the original single-cone technique. Objective: The aim of this study was to verify if either .02 or .06 tapered gutta-percha master cone would better fit into the working length of teeth shaped using ProTaper rotary system. Material and methods: Thirty distobuccal root canals of mandibular molars were shaped using F2 ProTaper, and size 40, 35, 30 and 25 0.6 or 0.2 tapered guttapercha cones were tested. The best fitting into the working length was recorded. The data were gathered and compared with size 25 by using Fisher’s exact test. Results: There was no statistically significant difference between groups (p = 0.4915). Sizes 30 and 35 were the most used. Conclusion: It can be concluded that both .02 and .06 tapered gutta-percha master cones showed best fitting in sizes larger than 0.25 mm in root canals shaped with ProTaper F2.

225 – RSBO. 2013 Jul-Sep;10(3):224-7 Machado� et al. – Analysis of apical fitting of .06 and .02 tapered gutta-percha master cones in root canals shaped with ProTaper rotary system

Introduction Root canal obturation aims at the sealing of the canal therefore hindering the communication of the oral cavity with the periapical structures and vice versa. Therefore, it is of extreme importance the adaptation of the master gutta-percha cone to root canal walls, mainly at apical level. Previous studies have demonstrated this difficulty even when there is the fitting of the cone into the working lenght [2, 16].

The rotary systems results in more conical and uniform preparations [12], enabling the execution of single-cone technique developed for this purpose, with easy and fast execution [4, 5].

The ProTaper system is the most used worldwide and has its gutta-percha cone according to the taper characteristics of its instruments to enable the execution of single-cone technique [14]. However, studies have demonstrated that ProTaper single-cone technique can show post-obturation leakages [3, 6, 11, 17, 19]. Accordingly, Machado [8] affirmed that automated systems resulted in larger preparations and advocates the use of modified single-cone technique with 0.6 tapered cones and diameters larger than the last size of the rotary instrument used in preparations with ProTaper system, searching for the best fitting of the single cone at the apical third.

Notwithstanding, studies are still lacking to confirm which diameter would be ideal to be used in most part of the cases in the modified technique.

Thus, considering that all modification must be analyzed on several technical and clinical aspects, the aim of this study was to verify if either .02 or .06 tapered gutta-percha master cone would better fit into the working length of teeth shaped using ProTaper rotary system.

Material and methods After the approval of the Ethical Committee in Research of the School of Dentistry of the University of São Paulo, thirty distobuccal roots of mandibular molars with straight canals and similar morphology were selected and checked by periapical radiographs. All specimens were standardized at 12 mm of length.

All canals were prepared according the technique of Machado et al. [9]. Briefly, the cervical and medium third were prepared with size 1, 2 and 3 Gates glidden burs (Dentsply Maillefer, Ballaigues, VD, Switzerland), followed by SX, S2 and F1 ProTaper rotary instruments (Dentsply Maillefer, Ballaigues, VD, Switzerland) through hand insertion towards apical direction and motor driven at 350 rpm with torque 3 and brushing movements applied to all canal walls. The working length was established at 1 mm short of the apical foramen and the

apical third was firstly prepared with size 15 and 20 K flexofile (Dentsply Maillefer, Ballaigues, VD, Switzerland), followed by S1, S2, F1 and F2 rotary instruments, as aforementioned described. All root canal preparations were executed under copious irrigation with 20 ml of 1% sodium hypochlorite (Fórmula e Ação, São Paulo, SP, Brazil), associated with light Endo PTC (Fórmula e Ação, São Paulo, SP, Brazil), followed by final irrigation with 5 ml of 1% sodium hypochlorite, 5 ml of 17% EDTA (Fórmula e Ação, São Paulo, SP, Brazil), and 5 ml of 1% sodium hypochlorite.

Next, with a wet root canal, the specimens were numbered and the fitting of 0.6 tapered cone (Dentsply Maillefer, Ballaigues, VD, Switzerland) was executed. Then, all data were recorded and the canals were again irrigated with 1% sodium hypochlorite and the fitting of 0.2 tapered cone (Dentsply Maillefer, Ballaigues, VD, Switzerland) was randomly performed not to influence on the results. The following sequence of diameters was used for all specimens: 40 – 35 – 30 – 25. The selected gutta-percha cone was the first one which best fitted into the working length, followed by confirmation through periapical radiograph. The data were gathered and compared with size 25 (which corresponds to F2 file) by using Fisher’s exact test with level of significance of 5%.

Results Only in two samples of group 1 size 25 fitted into the working length, the other samples of group 1 and all samples of group 2 fitted at larger diameters.

The comparison between groups did not show statistically significant differences (p = 0.4915).

Sizes 30 and 35 were the most used (graph 1).

Graph 1 – Distribution of the diameter most fitted at the working length

226 – RSBO. 2013 Jul-Sep;10(3):224-7 Machado� et al. – Analysis of apical fitting of .06 and .02 tapered gutta-percha master cones in root canals shaped with ProTaper rotary system

Discussion The searching for simplicity and rapidity is constant in all technical procedures in all research areas. In Endodontics, this is clear both for the preparation – in which automated techniques are used –, and for obturation exemplified by singlecone technique. However, these objectives should be also associated with quality, once they can define either the treatment success or failure.

Concerning to root canal obturation, several techniques have been proposed and the presence of the solid filling material such as gutta-percha is of extremely importance because endodontic cements can be solubilized resulting in spaces which allow bacterial penetration towards inside or outside the root canal [7, 15].

The ProTaper system has seemed to be faster than the other rotary systems [13]. It presents specific cones aiming to single-cone obturation.

Notwithstanding, the modification of this technique proposed by the manufacturer allows the use of .06 tapered cones with larger apical diameters [8].

The results found in this present study showed the positive results towards the modification because only two of the 60 samples tested (30 per group) exhibited apical diameter of 0.25 mm corresponding to F2 ProTaper, fact that confirms the hypothesis that preparations finished with F2 instruments result in diameters larger than 25.

This finding can justify the high rate of leakage found by prior studies in literature with obturations executed by the original technique proposed by the manufacturer [3, 6, 11, 17, 19].

Concerning to apical fitting, a study conducted by van Zyl et al. [18] exhibited that customized gutta-percha cones (modification of the original standardization), resulted in less empty spaces at the apical third. Accordingly, other studies showed the compatibility of greater filling of root canal by gutta-percha through the modified technique. The quantification of the filling material in mandibular molars prepared with ProTaper instruments and filled with .06 tapered guttapercha single cone showed lesser amount of cement at the apical third than those prepared by hand instrumentation and filled with lateral condensation [10]. Similar results were seen when mandibular pre-molars were prepared with ProTaper and obturated either by single-cone technique proposed by the manufacturer or by modified .06 tapered gutta-percha, resulting in greater gutta-percha filling when .06 tapered gutta-percha cone was used [1].

Clinically, F2 cone seems to be well fitted to the working lenght, but this could have occurred because the cone had fitted at the other thirds, giving the false impression of apical fitting.

Therefore, .02 tapered gutta-percha cones were used in this present study as a control group.

There were no statistically significant differences between .02 and .06 tapered gutta-percha cones.

However, the latter avoids the use of great amount of secondary gutta-percha points for root canal filling, therefore characterizing the single-cone technique as faster than the lateral condensation by using .02 tapered gutta-percha cone [4].

Based on the aforementioned discussion and the results of this study, the modified technique seemed to reach its goals. However, further studies are necessary to confirm its efficacy within biological and microbiological thresholds of Endodontics.

Conclusion Both .02 and .06 tapered gutta-percha showed better fitting in diameters larger than 0.25 mm in root canals prepared and finished with F2 ProTaper.

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8. Machado MEL. Endodontia da biologia à técnica.

1. ed. São Paulo: Santos; 2007.

9. Machado MEL, Sapial LAB, Cai S, Martins GHR, Nabeshima CK. ��������������������������������� Comparison of two rotary systems in root canal preparation regarding disinfection. J Endod. 2010 Jul;36(7):1238-40.

15. Peters DD. Two-year in vitro solubility evaluation of four gutta-percha sealer obturation techniques. ���������������������������� J Endod. 1986 Apr;12:139-45.

16. Souza RA, Andrade SM, Bahia A. Avaliação da interferência do travamento do cone principal de guta-percha no selamento apical. JBE. 2003 AprJun;4(12):119-21.

10. Machado MEL, Shin RCF, Zólio AA, Pallotta RC, Nabeshima CK. Confronto tra la quantità di sigillante nell’otturazione canalare con l’uso di strumentazione e tecniche d’otturazione diverse.

Il Dent Mod. 2010 Sep;28:50-6.

17. Taşdemir T, Er K, Yildirim T, Buruk K, Çelik D, Cora S et al. ���������������������������������� Comparison of the sealing ability of three filling techniques in canals shaped with two different rotary systems: a bacterial leakage study. Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2009 Sep;108(3):e129-34.

11. Mahera F, Economides N, Gogos N, Beltes P. Fluid-transport evaluation of lateral condensation, ProTaper gutta-percha and warm vertical condensation obturation techniques. Aust Endod J. 2009 Dec;35(3):169-73.

18. van Zyl SP, Gulabivala K, Ng Y-L. Effect of customization of master gutta-percha cone on apical control of root filling using different techniques: an ex vivo study. Int Endod J. 2005 Sep;38:658-66.

12. Moore J, Fitz-Walter P, Parashos P. A microcomputed tomographic evaluation of apical root canal preparation using three instrumentation techniques. Int Endod J. 2009 Dec;42:1057-64.

19. Yücel AÇ, Çiftçi A. Effects of different root canal obturation techniques on bacterial penetration.

Oral Surg Oral Med Oral Pathol Oral Radiol Endod.

2006 Oct;102(4):e88-92.

ISSN: Electronic version: 1984-5685 RSBO. 2013 Jul-Sep;10(3):228-33

Original Research Article

Clinical effectiveness of light-curing units of the School of Dentistry of the Federal University of Goias Laís Santos Gonçalves1 Mércia Bráulio Gonçalves1 Marília Morais Martins1 Gersinei Carlos de Freitas1 Lawrence Gonzaga Lopes1 Terezinha Jesus Esteves Barata1 Corresponding author: Terezinha Jesus Esteves Barata Avenida Universitária, esquina com 1.ª Avenida, s/n, Setor Universitário CEP 74605-220 – Goiânia – GO – Brasil E-mail: terezinhabarata@yahoo.com.br 1

Department of Prevention and Oral Rehabilitation, School of Dentistry, Federal University of Goias – Goiânia – GO – Brazil.

Received for publication: February 14, 2013. Accepted for publication: February 22, 2013.

Keywords: light sources; polymerization; resin composites.

Abstract Introduction: The clinical longevity of the procedures is directly associated to the adequate activation (photopolymerization) of adhesive restorative materials. Objective: To evaluate and compare by allocation the conservation status and power density of the light-curing units available at the School of Dentistry of the Federal University of Goias (FO/FUG) for clinical care. Material and methods: The following information and specific techniques of all light sources existing at FO/UFG, available for clinical care in 2011, were collected: dental/ambulatory clinic where they are located, type of source [device of halogen light and light-emitting diode (LED)], brand, parallelism test (halogen light sources), state of conservation of the light transmitter tip, density of the potency/ intensity/irradiance in mW/cm 2 and acquisition date. The data obtained were submitted to one-way ANOVA (Analysis of Variance) and Turkey test for multiple comparisons (P < 0.05). Results: In the second half of 2011, FO/UFG had 20 light sources (04 halogens and 16 LEDs), of which 90% were found in inadequate condition and 55% of those with power density less than 300 mW/cm2. There

229 – RSBO. 2013 Jul-Sep;10(3):228-33 Gonçalves� et al. – �������������������������������������������������������������� Clinical effectiveness of light-curing units of the School of ���������� Dentistry of ������� the Federal �������� ����������� University of �������� Goias

was no statistically significant difference in the power density between halogen and LED sources tested (P = 0.526). Likewise, no statistical difference was observed between the power density of the light sources (LED) placed at the Clinic II and III (P = 0.479). Also there was no statistically significant difference between the light sources (LED Halogen X) at the Clinic I (P = 0.943). Conclusion: The light sources regardless of the clinic in which they were located presented mostly with inadequate clinical effectiveness in terms of their conservation status and power density.

Introduction The advancement of aesthetical Dentistry is inter-related to the improvement of both the adhesive restorative materials and the light-curing systems for activation of these materials [3, 15, 22].

Among the adhesive materials available in dental market, resin composites have been increasingly used in current oral rehabilitation because they attend the function and aesthetical expectations [3, 13].

Resin composites are composed by three main components: organic matrix, inorganic filler and bonding agent [14]. Bis-GMA (bisphenol Aglycidyl methacrylate) and/or UDMA (urethane dimethacrylate), associated with monomers of low molecular weight as TEGDMA (triethylene glycol dimethacrylate) and EGDMA (ethylene glycol dimethacrylate), comprised the components of the organic matrix [7]. The inorganic filler particles within the organic matrix aim to ameliorate the mechanical properties, viscosity and degree of conversion of the resin composites [23]. The silane, on the other hand, is the bonding agent most common in the composition of resin composites with the aim of linking the filler particles to the organic matrix. The accelerator/initiator system completes the composition of the resin composites, which can be chemically or physically activated by this system. The chemical activation occurs through a reaction between the benzoyl peroxide and the tertiary amine respectively within the base paste and the catalyst paste [12]. On the other hand, the physical activation occurs when the photoinitiators within the resin composites are sensitized by the light sources or light-curing devices [7]. Among the photoinitiators, camphorquinone can be emphasized which exhibits a wavelength around 450 to 500 nanometers, with absorption peak at the 460 nm band of light [21].

Among the light sources available in dental market, the light emitting diode devices (LEDs) have been an alternative to the halogen light sources [16].

They emit light at specific and narrow wavelength bands, generally at the range between 440 and 500 nanometers, making them an efficient light source for resin composites [15, 19, 24].

Additionally to the efficiency in photoactivation, LEDs are also a light source of longer clinical durability, lower cost, and lower maintenance than other light sources [8, 15, 19].

Regardless of the activation system (chemical or physical) of a resin composite, its activation aims to obtain a uniformly and deeply high conversion of the material, associated with low stress of contraction therefore assuring the clinical longevity of the restoration [6]. Thus, the success of the restorative procedure using resin materials is directly related to the adequate activation of the restorative procedure [25]. Concerning to the physical activation (photopolymerization) of resin composite, some factors are essential: density of potency/intensity/irradiance, time of exposure, distance from the light transmitter tip to the material to be light-cured, and properties of the resin composites [1, 6].

To obtain the adequate characteristics of the resin composites, most of the manufactures recommend the use of an intensity of light/irradiance or minimum power density of 400 mW/cm² [5, 11] associated with an exposure time between 20 and 40 seconds [9].

St ill rega rding to t he dista nce from t he transmitter tip to the resin material to be lightcured, it is emphasized that the distance should be as close to the material as possible because the light intensity tend to decrease as the tip is moved away [6].

Consequently, the lack of photoactivation is one of the main factors limiting the clinical success of the restorations with resin composites [3, 19, 20].

This occurs because the lack of photoactivation of the resin composite mostly causes the superficial staining and marginal microleakage [18].

230 – RSBO. 2013 Jul-Sep;10(3):228-33 Gonçalves� et al. – �������������������������������������������������������������� Clinical effectiveness of light-curing units of the School of ���������� Dentistry of ������� the Federal �������� ����������� University of �������� Goias

These aspects are related to the improper polymerization of the resin composite and to the increase in the content of the residual monomers [2]. Thus, the conservation of the light sources, a nd consequent ly, t hei r power densit y may influence negatively on the mechanical and physical properties of the resin materials. In this context, the aim of this present study is to evaluate the conservation and compare the power density of the light sources available in the School of Dentistry of the Federal University of Goias (FO/UFG) used in the clinical care. The null hypothesis is that the light sources existing in the clinics of FO/UFG had similar conservation and power density.

Results In the second semester of 2011, FO/UFG had 20 light sources, of which 4 were halogens (Dabi Atlante) and 16 were LEDs [DMC (4), Schuster (9) and Sanders (3)]. These light sources were used in the Dentistry graduation and post-graduation courses and were located at 4 dental clinics (figure 1).

Material and methods The follow ing information a nd technica l specifications of all light sources existing in the clinics of FO/UFG and available for clinical care were gathered: the clinic where the device was located, type of source (halogen and LED), brand, parallelism test (halogen light sources), state of conservation of the light transmitter tip, density of the potency/intensity/irradiance in mW/cm2 and acquisition date.

The pa ra l lel ism test wa s conducted for the halogen light sources. This test assess the performance of the optical fiber through the contact of the light transmitter tip onto a text printed, when it is possible to visualize it with distinctness the parallelism is considered as positive; if the text is blurred the text is considered as negative [3].

The light intensity or power density of each light source was verified through a radiometer (Curing Radiometer Model 100 p/n – 10503, Demetron Research Corp., USA), according to the protocol proposed by Marson et al. [15] in mW/cm². To measure the power density, the active tip of the light source was placed centrally and perpendicularly to the radiometer and then three readings were performed, so that an arithmetic average was obtained. The first reading was executed for 10 seconds after the light source was switched on, the second and third readings were carried out consecutively with intervals of 30 seconds between each other.

T h e d a t a o bt a i n e d w e r e s u b m i t t e d t o descriptive statistical analysis, one-way analysis of variance (Anova), and Tukey test for multiple comparisons. The level of significance adopted was 5% (P < 0.05).

Figure 1 – Distribution of the light sources of FO/UFG at the dental clinics

The light sources were employed in nine disciplines of graduation: Primary Care Clinic I and II, Children’s Clinic I and II, Internship in Integrated Clinical I, II, III and IV and Emergency Clinic. Of these disciplines, the Emergency Clinic is taught in its own clinic, two disciplines are taught in Clinic I (Children’s Clinic I and II), two in Clinic II (Primary Care Clinic I and II) and four disciplines in Clinic III (Integrated Clinic I, II, III and IV). This totalized about 100 hours per week of usage of the clinics for the graduation activities. Eventually, the discipline of Surgery and the Extension projects as well as the post-graduation courses utilized the clinics and consequently the light sources when necessary. Concerning to the time of acquisition, it was observed that all light sources of FO/UFG were acquired for more than six months prior to the study, and there had not been any program of periodical preventive maintenance.

In relation to the conservation state, it was observed that 90% of the light sources of FO/UFG showed an inappropriate conservation state, with cracks and/or fractures, as well as residues of resin composite and/or adhesive agent in the light transmitter tip. This study still revealed that 75% of the halogen transmitter light tip exhibited a negative parallelism.

Concerning to the power density, 55% of the light sources showed density lower than 300 mW/cm2 (50-225 mW/cm2) and 35% of the sources exhibited density greater or equal to 400 mW/cm2 (400 – 625 mW/cm2) (figure 2).

231 – RSBO. 2013 Jul-Sep;10(3):228-33 Gonçalves� et al. – �������������������������������������������������������������� Clinical effectiveness of light-curing units of the School of ���������� Dentistry of ������� the Federal �������� ����������� University of �������� Goias

Figure 2 – Power density in mW/cm² of the light sources used in the clinics of FO/UFG

The power density values in mW/cm² of the light sources of the clinics of FO/UFG are seen in tables I and II and are divided per type of source and location in the clinic.

Table I – Power density in mW/cm2 of the halogen and LED light sources in the clinics of FO/UFG

Light sources Power densityin mW/cm2

Halogen

LED

Mean

237.5a

292.2a

Standard deviation

59.5

190.7

Minimum

200

50

Maximum

325

625

One-way Anova and Tukey test (P = 0.526) * Equal superscript letter does not indicate significant statistical difference

Table II – Power density in mW/cm2 of the light sources per location in the clinic

I

Dental Clinica Power density in mW/cm2

II

III

Halogen

LED

Halogen + LED

LED

LED

Mean

250

255

252

337.9

257.1

Standard deviation

66.1

77.8

60.9

186.5

225.3

Minimum

200

200

200

50

50

Maximum

325

310

325

550

625

Emergency clinic: it was excluded from the statistical analysis because it had only one light source available presenting power density of 200 mW/cm2 a

There were no statistical significant differences in the power density among the LED light sources located at the Clinics II and III (P = 0.479). Additionally, there were no statistically significant differences between LED and halogen light sources at Clinic I (P = 0.943). Based on these results, the null hypothesis was accepted.

Discussion This present study revealed an inadequate conservation state of the light sources available for the clinical care at FO/UFG. Similar situation was observed by Baldi et al. [3] in the School of Dentistry of the State University of Ponta Grossa, in which 69.23% of the light sources were inadequate for

232 – RSBO. 2013 Jul-Sep;10(3):228-33 Gonçalves� et al. – �������������������������������������������������������������� Clinical effectiveness of light-curing units of the School of ���������� Dentistry of ������� the Federal �������� ����������� University of �������� Goias

use. Likely, in the Dentistry Clinic of the State University of Londrina, Beltrani et al. [4] observed that, regarding to the conservation state of the light transmitter tips, 91.7% exhibit debris, 83.3% were not capable of transmitting light and 16.7% showed any type of fracture.

It is important to emphasize that the performance of the halogen light sources can be decreased by the inadequate maintenance of the optic fiber and light transmitter tip [4, 17]. It is important to consider that the inadequate conservation of the light sources is related to a smaller intensity of light emission [3-5, 15, 27]. This premise was corroborated by the results obtained by this present study. It can be affirmed that the conservation state of the light sources was directly related to the power density observed. Pascotto et al. [17] still emphasized that the adequate photopolymerization of a resin composite is linked to the light intensity and to the exposure time. It is known that the halogen light devices demand a minimum light intensity of 400 mW/cm² for the adequate photoactivation of the resin composites. On the other hand, LED sources required a minimum light intensity of 300 mW/cm² and at least 20 seconds of exposure time [26].

This present study observed that 65% of the light sources of FO/UFG exhibited power density smaller than 400 mw/cm² (figure 2). Similar condition was found by Borges et al. [5] in the dental clinics of the Federal University of Maranhao. The authors verified that 68% of the light sources tested showed power density smaller than 400 mw/cm².

Likely, studies on the evaluation of the power density in private dental offices have observed these same outcomes, such as those by Freitas et al. [10] in the city of São Luís (MA) and Marson et al. [15] in Maringá (PR). Freitas et al. [10] observed that 46.01% of LED light sources tested exhibited power density smaller than 100 mW/cm²; 44.17% showed power density between 100-400 mW/cm²; and 9.82% presented density greater or equal to 400 mW/cm². For the halogen sources, the authors verified a density between 100 and 400 mW/cm² in 94.73% of the sources tested, while in 5.27% they found an intensity lower than 100 mW/cm²; none light source showed intensity greater than 400 mW/cm². Marson et al. [15] found that 50% of the halogen light sources exhibited power density above 300 mW/cm², 20% between 200-300 mW/cm² and 30% lower than 200 mW/cm².

The literature has described that this clinical situation can result in aesthetic involvement, marginal microleakage, and decrease of the physical and biological properties of the resin composites [7].

Based on this aforementioned discussion, it can be affirmed that the conservation state of the light source directly interfered in the photoactivation effectiveness. Baldi et al. [3], Beltrani et al. [4], Borges et al. [5] and Freitas et al. [10] affirmed that it is necessary the periodical maintenance of the light sources, once their conservation state is related to the power intensity and consequently with the polymerization effectiveness. Therefore, the clinic staff must be aware of these requirements regarding the use of the light sources and the need of a preventive maintenance protocol to achieve the photopolymerization effectiveness.

Conclusion • The clinical effectiveness of the light sources was dependent on their conservation state and power density, which were inadequate for most of the sources tested; • The light sources in clinical use exhibited similar conditions of conservation state and power density, regardless the clinic where they were located.

References 1. Accetta DF, Magalhães Filho TR, Weig KM, Fraga RC. Influência dos fotopolimerizadores (luz halógena x LED) na resistência à compressão de resinas compostas. Fac ��������������� Odontol Rev.2008 SepDec;49(3):17-9.

2. Bagis YH, Rueggeberg FA. The effect of postcure heating on residual, inreacted monomer in a commercial resin composite. Dent ����������������� Mater. 2000 16:244-7.

3. Baldi RL, Teideri LD, Leite TM, Martins R, Delgado LAC, Pereira SK. Intensidade de luz de aparelhos fotopolimerizadores utilizados no curso de Odontologia da Universidade Estadual de Ponta Grossa. Publ UEPG Ci Biol Saúde. 2005 Mar;11(1):39-46.

4. Beltrani FC, Caldarelli PG, Kossatz S, Hoeppner MG. Avaliação da intensidade de luz e dos componentes dos aparelhos fotopolimerizadores da Clínica Odontológica da Universidade Estadual de Londrina. Revista Brasileira de Pesquisa em Saúde. 2012 14(1):5-11.

5. Borges FMGS, Rodrigues CC, Freitas SAA, Costa JF, Bauer J. Avaliação da intensidade de luz dos fotopolimerizadores utilizados no curso de Odontologia da Universidade Federal do Maranhão.

Rev Ciênc Saúde. 2011 Jan-Jun;13(1):26-30.

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6. Davidson CL, De Gee AJ. �������������������� Light-curing units, polymerization, and clinical implications. J Adhes Dent. 2000;2(3):167-73.

7. Ferracane JL. Resin composite – state of the art.

Dent Mater. 2011 Jan;27(1):29-38.

8. Firoozmand LM, Balducci I, Araújo MAM. Influência da fotopolimerização e da cor da resina composta na microdureza. Pesq Bras Odontoped Clín Integr. 2009 Jan-Apr;9(1):37-42.

9. Freitas ABDA, Gomes HR, Guimarães FBR, Marinho VA, Barros LM. Influência do tipo de aparelho fotopolimerizador na absorção de água por restaurações de resina composta. Inst Ciênc Saúde Res. 2008;26(1):65-9.

10. Freitas SAA, Costa JF, Bauer JRO. Avaliação da intensidade da luz dos aparelhos fotopolimerizadores utilizados em clínicas odontológicas de São Luís – MA. Rev Pesq Saúde.

2011 May-Aug;12(2):27-31.

11. Godoy EP, Pereira SK, Carvalho BM, Martins GC, Franco APGO. Aparelhos fotopolimerizadores: elevação de temperatura produzida por meio da dentina e durante a polimerização da resina composta. Rev Clín Pesq Odontol. 2007 JanApr;3(1):11-20.

12. Grando PR, Magnani MBBA, Pereira AC, Meneghim MC, Kurame M, Tavares SW. Colagem de bracket ortodôntico com resina composta e com ionômero de vidro. J Bras Ortodon Ortop Facial.

2002 Mar-Apr;7(38).

13. Loretto SC, Silva AKS, Brandão RKZ, Carneiro MCM, Souza Júnior MHS. Avaliação in vitro da fenda de contração de polimerização formada por diferentes resinas compostas universais. RSBO. ������ 2010 Oct-Dec;7(4):430-8.

14. Lukaszczyk J, Janicki B, Frick A. Investigation on synthesis and properties of isosorbide based bis-GMA analogue. J Mater Sci Mater Med. 2012 May;23(5):1149-55.

17. Pascotto RC, Pereira SK, Carneiro FP. Avaliação dos aparelhos fotopolimerizadores utilizados em clínicas odontológicas. J Bras Dent Estét. 2003 Jan-Mar;2(5):29-35.

18. Prado Junior RR, Moita Neto JM, Mendes RF, Parente DM. Estudo quimiométrico qualitativo da polimerização de resina composta. RGO. 2008 Jul-Sep;56(3):261-6.

19. Reston EG, Barbosa AN, Busato ALS, Klein Junior CA, Carli G, Carvalho CM et al. Microdureza de resina composta polimerizada com LEDs de diferentes gerações e luz halógena. Stomatos. 2008 Jul-Dec;14(27):17-25.

20. Rodrigues Neto E, Elossais AA, Munõz Cháves OF, Pereira NRS, Silva PG, Saad JRC. Estudo comparativo de aparelhos fotopolimerizadores para determinar o grau de conversão de resinas compostas utilizando o espectrofotômetro de infravermelho. RGO. ������������������������������� 2007 Oct-Dec;55(4):357-61.

21. Rueggeberg FA. Contemporary issues in photocuring. Compend Contin Educ Dent Suppl.

1999 Nov;25:4-15.

22. Rueggeberg FA. State-of-the-art: dental photocuring – a review. Dent Mater. 2011 Jan;27(1):39-52.

23. Ruyter IE, Oysaed H. Composites for use in posterior teeth: composition and conversion. �� J Biomed Mater Res. 1987 Jan;1:11-23.

24. Souza AR, Youssef MN, Turbino ML, Mello B. Avaliação do grau de polimerização de duas resinas compostas utilizando luz halógena e dois diferentes tipos de LEDs. RPG ������������������ Rev Pós Grad.

2005;12(4):474-80.

25. Strydom C. Dental curing lights – maintenance of visible light curing units. S ����������� ADJ. 2002 Jun;57(6):227-33.

15. Marson FC, Mattos R, Sensi LG. Avaliação �������������� das condições de uso dos fotopolimerizadores. Rev ���� Dentística. 2010;9(19):15-20.

26. Vieira GF, Freire IA, Agra CM, Goveia JC, Matson E. Análise da irradiação de diversos aparelhos fotopolimerizadores. Rev ����������������� Odontol Univ São Paulo. 1998 Oct-Dec;12(4).

16. Nomoto R, McCabe JF, Nitta K, Hirano S. Relative efficiency of radiation sources for photopolymerization.

Odontology. 2009;97:109-14.

27. Wunderlich Junior AE. ���������������������� Avaliação de potência de fotopolimerizadores à LED utilizados em consultórios. Ortodontia SP. 2009;42(2):95-100.

ISSN: Electronic version: 1984-5685 RSBO. 2013 Jul-Sep;10(3):234-9

Original Research Article

Effect of Gates Glidden, La Axxess, SX and ultrasound on the circularity and area of mesial canals of mandibular molars Etevaldo Matos Maia Filho1 Erick Miranda Souza2 Edimar Oliveira Meneses1 Cláudia de Castro Rizzi1 Corresponding author: Etevaldo Matos Maia Filho Rua Duque Bacelar, Q. 1, Casa 11 – Altos do Calhau CEP 65071-785 – São Luís – MA – Brasil E-mail: rizzimaia@yahoo.com.br 1 2

Dentistry Course, Ceuma University – São Luís – MA – Brazil.

Dentistry Course, Florence Institute – São Luís – MA – Brazil.

Received for publication: August 7, 2012. Accepted for publication: March 14, 2013.

Keywords: Endodontic; root canal; instrumentation.

Abstract Introduction: Biomechanical preparation must provide a taper shape at crown-apex direction for root canal resulting in adequate space for irrigation and enabling an effective obturation. However, this stage requires a cervical preparation aiming to remove the interferences to make the access to the apical portion easy for instrumentation. Objective: To evaluate in vitro the effect of coronal f laring on the root canal area and in the circularity of mesial canals of lower molars after using Gates Glidden, La Axxess, Sx file or a ultrasonic TU-24tip. Material and methods: Twenty-four lower molars had their roots embedded into acrylic resin. Then the roots were sectioned horizontally at 2 mm below the cementenamel junction. The sections were photographed before and after the different coronal flaring. All images were analyzed using Image J software to calculate the root canal area and the circularity of the root canal. One-way Anova was used to compare the circularity among the groups, while Kruskal-Wallis test was used for comparing the areas. A Pearson test was used to correlate root canal area and circularity data. Results: There was no significant difference among the groups neither for the circularity (p > 0.05) nor for the

235 – RSBO. 2013 Jul-Sep;10(3):234-9 Maia Filho� et al. – ���������� Effect of Gates ������ Glidden, ��������� La ��� Axxess, �������� SX ��� and ���������������������������������� ultrasound on the circularity and ������������ area of mesial ����������������� canals of mandibular molars

root canal area (p > 0.05). There was observed a significant inverse correlation between the root canal area and the circularity (r2 = 0.135; p < 0.05). Conclusion: Different coronal flaring techniques have produced similar root canal area and circularity, however the larger the canal area the lower the circularity.

Introduction Biomechanical preparation is an indispensable phase for endodontic treatment success. It must provide a taper shape at crown-apex direction resulting in adequate space for irrigation and enabling an effective obturation. Additionally, for a better root canal cleaning and shaping, root canal preparation must provide free and direct access the apical portion. Crown-down instrumentation techniques [6] provided the prior flaring of the cervical third for the further access to the apical area. Consequently, an inaccurate preparation of the cervical third will compromise this access mainly in curved roots, as in the mesial roots of mandibular molars and buccal roots of maxillary molars. Cervical flaring [1] aims to make straight the curvatures of the cervical and medium thirds by removing the interferences to make easy the access to the apical area and to decrease the stress during instrumentation [8], consequently diminishing the frequency of fracture of the instruments [10]. Additionally, when cervical flaring is not previously executed, an alteration of the working lenght may occur during the instrumentation of the canals [17].

The circularity is defined as the quality or characteristic of which is round and it can vary from values of 1 (perfect circle) to 0 (straight).

Mathematically, it is obtained through the circularity formula = 4�� π� ������� (area/ ��������� perimeter2). Cervical flaring should be as circular as possible, decreasing the amount of reentrances, favoring obturation because gutta-percha points exhibit a circular cross-section.

Notwithstanding, it is mandatory that this maneuver preserve the risk zone, avoiding perforations at the furcation area; for this purpose, several tools have been used, among them, the use of Gates Glidden and La Axxess burs [17].

Nickel-t it a n iu m i nst r u ment s have been incorporated to the endodontic armamentarium because of their good flexibility, which make them suitable for the preparation of curved canals.

ProTaper system for instrumentation (Dentsply/ Maillefer, Ballaigues, Switzerland) comprises the SX instrument aiming to the enlargement of the cervical third of the root canal for a posterior apical preparation.

The ultrasound has been used for apical preparations in parendodontic surgery [3], lateral condensation technique [2], placement and removal of the calcium hydroxide inside root canals [9, 20]. In the endodontic market, ultrasound points are available to execute the cervical flaring of the root canals; however, there have been no studies in the literature on evaluating the capability of ultrasound in cervical flaring. Thus, the aim of this study is to assess the effect of size 3 Gates Glidden bur (Dentsply/Maillefer), size 1 La Axxess bur (SybronEndo, USA), SX (Dentsply/Maillefer) and ultrasound TU-24 tip (Trinity, São Paulo, SP, Brazil) on the amount of dentine removed and on the circularity of the mesial root canals of mandibular first molars.

Material and methods This present study was approved by the Ethical Committee in Research of the University Center of Maranhao under protocol number #0078/111.

Twenty-four mandibular human first molars were selected and their mesial-buccal and mesial-lingual canals were used. The teeth were cleaned with 5% de NaOCl for 24 hours, followed by the carefully removal of the periodontal tissue and calculus.

Next, the teeth were washed under running water, dried and stored in 10% formalin solution.

The teeth were embedded into acrylic resin (Artigos Odontológicos Clássico Ltda., São Paulo, SP, Brazil) through using a stainless steel muffle system similar to that described by Kuttler et al.

[14]. The long axis of the tooth was positioned perpendicularly to the horizontal plane. After the resin polymerization, the teeth were kept at environment temperature for 48 hours.

The coronal access was executed with the aid on number 1016 cylindrical drill (KG Sorensen®, São Paulo, SP, Brazil), under constant irrigation and complemented by Endo-Z drill (Dentsply Maillefer, Ballaigues, Switzerland).

The mesial roots were initially negotiated with a size 10 K file without aiming to the flaring of the root canal.

236 – RSBO. 2013 Jul-Sep;10(3):234-9 Maia Filho� et al. – ���������� Effect of Gates ������ Glidden, ��������� La ��� Axxess, �������� SX ��� and ���������������������������������� ultrasound on the circularity and ������������ area of mesial ����������������� canals of mandibular molars

Two previous radiographs of each mesial root were performed with a size 10 file inside the root canal: at the buccal-lingual and mesial-distal directions. The exposure time and the x-ray processing technique were standardized. The radiographs were analyzed in a dark room with the aid of a negatoscope and x3.5 magnifying glass. Only teeth with moderate curvature roots between 10-35º were used, employing the method of Schneider [18].

With the aid of a precision cutting machine at low speed (Extec® Labcut 1010, Enfield, CT, USA), the blocks were cut perpendicularly to their long axes, 2 mm below the enamel-cementum junction.

The cuts were photographed with a resolution of 7 megapixels by using a digital camera (PowerShot G12, Canon, Japan) linked to an operating microscope (Opto, São Carlos, SP, Brazil) at X20 magnification.

The images captured were processed digitally in Adobe Photoshop CS3 software (Adobe System Incorporated, USA), and the root canal area was delimited prior to the procedures. The images were saved in jpeg format.

Each sample was relined in the muffle and the patency was tested with the aid of a size 10 K file to check for the presence of obstructions due to the cutting procedure.

An experienced operator equally trained for the use of the instruments, using only a single instrument of each type, performed all cervical flarings. The techniques were executed at a pre-established sequence so that each technique prepared 12 canals: 6 mesial-lingual and 6 mesial-buccal, totalizing 48 canals.

Gates Glidden, La Axxess and SX instruments were used in a straight handpiece (1:1; Kavo, Joinville, SC, Brazil) together with an endodontic electric motor (Endo Pro Torque/Driller, Jaguaré, SP, Brazil). Size 3 Gates Glidden and size 1 La Axxess were employed at a speed of 6000 rpm, while a speed of 300 rpm was used for SX instruments. The ultrasound TU-24 tip (Trinity, São Paulo, SP, Brazil) was used together with an ultrasound device (Profi Class - Dabi Atlanti, Ribeirão Preto, São Paulo, Brazil), at Endo mode and maximum power for 60 s and water irrigation.

After preparation, the canals were irrigated with 1% sodium hypochlorite with the aid of a syringe and size 31 gauge needle (Ultradent Inc, South Jordan, UTA, USA).

After the preparation, the cuts were removed from the muffle and again photographed similar to previously described. The images, before and after preparation, were transferred to Image J software version 1.46r (http://rsbweb.nih.gov/ij/). To calculate the area and circularity of the root canal,

a configuration was carried out in the Analyze/Set Measurements menu by selecting the options Area and Shape descriptors. After delimiting the area regarding to the root canal, the values of area and circularity were obtained by clicking in Analyze/Measure.

The data of the measurements performed on the images before and after the cervical flaring, both for circularity and area, were typed in sheets of Microsoft Excel 2007 for Windows (Microsoft Corporation® USA), and the statistical analyses were executed with SPSS 18.0 software (SPSS Inc, Chicago, IL, USA).

After data tabulation, a descriptive statistical analysis was conducted by emphasizing the means and standard deviations for each treatment type.

To verify whether there were differences among groups in relation to area and circularity, firstly tests were applied to evaluate whether the area and circularity values of the mesial-buccal and mesiallingual canals would be statistically equal to be included in a single group and whether the distribution was normal and homogeneous. The t test did not exhibit statistically significant difference in either the circularity or area between the mesial-buccal and mesial-lingual canals (p > 0.05). The normality (Shapiro-Wilk test) and homogeneity (Levene test) hypothesis was satisfied for circularity (P > 0.05), but not for the area (p < 0.05). Thus, a parametric test was applied for the circularity (one-way Anova) and a non-parametric test for area (Kruskal-Wallis). Pearson correlation test was applied between the increase of the area and the increase of the circularity. For all tests, the level of significance was set at 0.05.

Results The area and circularity mean values are seen in table I. There were no statistical significant differences among treatments for either circularity (p > 0.05) or area (p > 0.05), that is, all preparations showed values statistically similar both for circularity and area.

Table I – Final mean and standard deviation values for circularity and area reached in the preparations with La Axxess, Gates Glidden, SX and ultrasound compared with the initial values

Area (mm2)

Circularity

Before preparation

0.44 (±0.35)

0.27 (±0.07)

Gates Glidden

1.14 (±0.83)

0.39 (±0.11)

La Axxess

0.96 (±0.87)

0.40 (±0.11)

SX

0.77 (±0.42)

0.39 (±0.07)

Ultrasound

0.68 (±0.34)

0.42 (±0.08)

237 – RSBO. 2013 Jul-Sep;10(3):234-9 Maia Filho� et al. – ���������� Effect of Gates ������ Glidden, ��������� La ��� Axxess, �������� SX ��� and ���������������������������������� ultrasound on the circularity and ������������ area of mesial ����������������� canals of mandibular molars

Graph 1 – Box plot graph evidencing the median, minimum and maximum values for the area after the cervical flaring as well as the variation of the experimental groups. There were no statistically significant differences among groups (p > 0.05)

There was a statistically significant negative correlation between the increase of the area and the increase of the circularity for all treatments (r2 = 0.135, p < 0.05). Therefore, the greater the area increase, the smaller the increase of the circularity, indicating that the enlargement of the canal area does not imply in better circularity of the preparation (graph 2).

Graph 2 – Relationship between the increase of the area and the increase of the circularity. There was an inverse relationship between the increase of the area and the increase of the circularity. The greater the between the increase of the area the smaller the increase of the circularity (r 2 = 0.135; p < 0.05)

238 – RSBO. 2013 Jul-Sep;10(3):234-9 Maia Filho� et al. – ���������� Effect of Gates ������ Glidden, ��������� La ��� Axxess, �������� SX ��� and ���������������������������������� ultrasound on the circularity and ������������ area of mesial ����������������� canals of mandibular molars

Discussion The muffle system [5] employed in this study enables comparing the area worn and the circularity after the cervical flaring and it has been used to evaluate the effect of the root canal instrumentation [12, 19, 21] and the impact of the preparation of the remnant of dentine post [15]. It is a simple method enabling an analysis before and after the cervical flaring and it is of easy reproduction.

According to Bower [4] the furcation area in mandibular molars is found 2 mm below the enamelcementum junction. Based on this knowledge, the teeth were sectioned at this same measurement. A similar criterion was adopted by Wu et al. [22].

The circularity is an important factor to be considered during the biomechanical preparation and varies between 0 (straight) and 1 (perfect circle). The initial mean value of circularity was of 0.27±0.07, showing little variation before the canals had been prepared. All preparations provided a gain of about 30% in circularity, without however, showing statistically significant difference among groups. Notwithstanding, a negative correlation between the increase of the area and the increase of the circularity was noted (r2 = 0.135, p < 0.05), exhibiting that the increase of the area decreased the circularity. In other words, a better circularity was obtained when there was a smaller weariness of the cervical area. Thus, the greater the area worn the smaller the circularity gain. These data are important, because one could think that the greater the area worn the greater would be the circularity; also, it shows that more conservative wear avoids damages to the furcation area and provides a more circular cervical area. By interpreting the r2 value, one can conclude that the variation in the increasing of the area accounted for 13.3% of the variation of the increase of the circularity, which demonstrates a significant medium effect size of an variable on another. In other words, although there would be other variables accounting for the circularity variation, the area variation was an important factor and it should be taken into consideration during the cervical f laring preparation. Gates Glidden drill provided the greater cervical flaring; however, it was the group together with La Axxess drill, in which the variation showed the greatest mean with standard deviations equal to 0.83 and 0.87, respectively. This large variation in cervical flaring provoked by Gates Glidden drill have already been evidenced in other studies [13, 22] and it is not clinically desirable because it can eventually reach the furcation area and cause perforation, as already demonstrated [11, 16].

The result of this study showed that La Axxess drill promoted an increase of area similar to that reached by Gates Glidden drill; however, it is known that this latter, differently from La Axxess drill, does not have taper, therefore executing a more uniform wear of the root canal. Thus, caution must be taken in the cervical preparation with these instruments. The preparations with SX files and ultrasound tips were more predictable, because they exhibited little variation. The possible explanation for this smaller wear variation in these groups would be the speed with which SX file was driven (300 rpm), which decreased the cutting action of this instrument; also, it is known that nickel-titanium instruments tend to become more centralized within the root canal than stainless steel instruments [7]. On the other hand, a greater control was obtained with the use of the ultrasound tip because it was adjusted to the entrance of the root canal, enabling a controlled wear. SX file presented the smallest mean of cervical dentine removal than Glidden and La A x xess drills; however, without statistically significant differences. Unlikely, Mahran and AboEl-Fotouh [16] concluded that Protaper system removed significantly less dentine from the cervical region than Gates Glidden drills.

Although the ultrasound has been well indicated for t he apica l prepa rat ion in pa rendodont ic surgeries [3], as far as we are concerned, this present study is the first evaluating its use in cervical preparation The ultrasonic diamond tip used in this study is not indicated for the cervical flaring and it was selected because of its similarity to La Axxess drill. Despite of its promising results, further studies are necessary to prove its clinical effectiveness considering other aspects such as the capacity of preserving the furcation region, decreasing the risk of perforation.

Conclusion Considering the limits of this study, it can be concluded that cervical preparations showed a similar increase of the area and circularity.

Notwithstanding, the greater the area increase, the greater the circularity increase.

References 1. Abou-Rass M, Frank AL, Glick DH. The anticurvature filing method to prepare the curved root canal. J Am Dent Assoc. 1980 Nov;101(5):792-4.

239 – RSBO. 2013 Jul-Sep;10(3):234-9 Maia Filho� et al. – ���������� Effect of Gates ������ Glidden, ��������� La ��� Axxess, �������� SX ��� and ���������������������������������� ultrasound on the circularity and ������������ area of mesial ����������������� canals of mandibular molars

2. Bailey GC, Cunnington SA, Ng YL, Gulabivala K, Setchell DJ. Ultrasonic condensation of guttapercha: the effect of power setting and activation time on temperature rise at the root surface – an in vitro study. ����������������������������������� Int Endod J. 2004 Jul;37(7):447-54.

3. Bernardes RA, de Moraes IG, Garcia RB, Bernardineli N, Baldi JV, Victorino FR et al.

Evaluation of apical cavity preparation with a new type of ultrasonic diamond tip. J Endod. 2007 Apr;33(4):484-7.

4. Bower RC. Furcation morphology relative to periodontal treatment. Furcation entrance architecture. J Periodontol. 1979 Jan;50(1):23-7.

5. Bramante CM, Berbert A, Borges RP. A methodology for evaluation of root canal instrumentation. J Endod. 1987 May;13(5):243-5.

6. Buchanan LS. The standardized-taper root canal preparation, part 1: concepts for variably tapered shaping instruments. Dent Today. 1998 May;17(5):54-60.

7. Carvalho LA, Bonetti I, Borges MA. A comparison of molar root canal preparation using stainless-steel and nickel-titanium instruments. J Endod. 1999 Dec;25(12):807-10.

8. Constante IG, Davidowicz H, Barletta FB, Moura AA. Location and angulation of curvatures of mesiobucal canals of mandibular molars debrided by three endodontic techniques. Braz Oral Res. 2007 Jan-Mar;21(1):22-8.

9. Deveaux E, Dufour D, Boniface B. Five methods of calcium hydroxide intracanal placement: an in vitro evaluation. ������������������������������� Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2000 Mar;89(3):349-55.

10. Ehrhardt IC, Zuolo ML, Cunha RS, De Martin AS, Kherlakian D, de Carvalho MC et al. ����������� Assessment of the separation incidence of Mtwo files used with preflaring: prospective clinical study. J Endod.

2012 Aug;38(8):1078-81.

11. Gluskin AH, Brown DC, Buchanan LS. A reconstructed computerized tomographic comparison of Ni-Ti rotary GT files versus traditional instruments in canals shaped by novice operators. Int Endod J. 2001 Sep;34(6):476-84.

12. Hulsmann M, Schade M, Schafers F. A comparative study of root canal preparation with Hero 642 and Quantec SC rotary Ni-Ti instruments.

Int Endod J. 2001 Oct;34(7):538-46.

13. Isom TL, Marshall JG, Baumgartner JC. Evaluation of root thickness in curved canals after flaring. J Endod. 1995 Jul;21(7):368-71.

14. Kuttler S, Garala M, Perez R, Dorn SO. The endodontic cube: a system designed for evaluation of root canal anatomy and canal preparation. J Endod. 2001 Aug;27(8):533-6.

15. Kuttler S, McLean A, Dorn S, Fischzang A. The impact of post space preparation with GatesGlidden drills on residual dentin thickness in distal roots of mandibular molars. J Am Dent Assoc. 2004 Jul;135(7):903-9.

16. Mahran AH, AboEl-Fotouh MM. Comparison of effects of ProTaper, HeroShaper, and Gates Glidden Burs on cervical dentin thickness and root canal volume by using multislice computed tomography.

J Endod. 2008 Oct;34(10):1219-22.

17. Schmitz Mda S, Santos R, Capelli A, Jacobovitz M, Spano JC, Pecora JD. Influence ���������������������� of cervical preflaring on determination of apical file size in mandibular molars: SEM analysis. Braz Dent J. 2008;19(3):245-51.

18. Schneider SW. A comparison of canal preparations in straight and curved root canals. Oral ��������������� Surg Oral Med Oral Pathol. 1971 Aug;32(2):271-5.

19. Souza EM, do Nascimento LM, Maia Filho EM, Alves CM. The �������������������������������������� impact of post preparation on the residual dentin thickness of maxillary molars. J Prosthet Dent. 2011 Sep;106(3):184-90.

20. van der Sluis LW, Wu MK, Wesselink PR. The evaluation of removal of calcium hydroxide paste from an artificial standardized groove in the apical root canal using different irrigation methodologies.

Int Endod J. 2007 Jan;40(1):52-7.

21. Wu MK, van der Sluis LW, Wesselink PR. The capability of two hand instrumentation techniques to remove the inner layer of dentine in oval canals.

Int Endod J. 2003 Mar;36(3):218-24.

22. Wu MK, van der Sluis LW, Wesselink PR. The risk of furcal perforation in mandibular molars using Gates-Glidden drills with anticurvature pressure. Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2005 Mar;99(3):378-82.

ISSN: Electronic version: 1984-5685 RSBO. 2013 Jul-Sep;10(3):240-4

Original Research Article

Influence of different surface treatments on the shear bond strength of a methacrylate resin composite repaired with silorane-based resin Leonardo Fernandes da Cunha1 Bruno Moreno Nascimento1 Samantha Shaffer Pugsley Baratto2 Carla Castiglia Gonzaga2 Adilson Yoshio Furuse2 José Mondelli1 Odirlei Arruda Malaspina3 Corresponding author: Leonardo Fernandes da Cunha Centro Odontológico Brasiliense – Brasília Shopping/SCN Quadra 5, Bloco A CEP 70710-500 – Brasília, DF – Brasil E-mail: cunha_leo@yahoo.com.br Department of Operative Dentistry, Endodontics and Dental Materials, Bauru School of Dentistry – Bauru – SP – Brazil.

Master of Science Program in Clinical Dentistry, Positivo University – Curitiba – PR – Brazil.

3 Superior School of Health Sciences, Amazonas State University – Manaus – AM – Brazil.

1 2

Received for publication: September 12, 2012. Accepted for publication: December 20, 2012.

Keywords: composite resins; shear strength; adhesives.

Abstract Introduction: When repairs are needed in restorations made with methacrylate-based resin composites, the clinician still has doubts whether it is possible to use a silorane-based material and which is the best procedure. Objective: To evaluate the shear bond strength between a methacrylate-based resin composite and a silorane-based material using different surface treatments. Material and methods: Eighty flat bases made with methacrylate resin composite (Filtek Z350 XT) were prepared (n = 8). The bases were stored into water at 37°C for one week. Ten groups were evaluated: G1 (control – no repair); G2 (surface grinding, washing, drying, adhesive and repair with Filtek Z350 XT); G3 (surface grinding, washing, drying, adhesive and repair with silorane – Filtek P90); G4 (surface grinding, washing, drying, adhesive, silane and repair with Filtek Z350 XT); G5 (surface grinding, washing, drying, application of silane, adhesive and repair with silorane – Filtek P90). All groups were kept at 37°C for 24 h

241 – RSBO. 2013 Jul-Sep;10(3):240-4 Cunha� et al. – ������������� Influence of different ������������������������������������������ surface treatments on the shear bond ������������������� strength of a methacrylate ����������������������������� resin composite repaired with silorane-based resin

in either water (G1 to G5) or ethanol (G6 to G10). The results were analyzed with one-way ANOVA and Tukey test (α = 0.05). Results: There were significant differences between groups (p < 0.001). Only repairs made with silane and Z350 XT (G4 = 46.2 ± 12.9; G9 = 48.1 ± 16.3) resulted in values similar to controls (G1 = 59.2 ± 15.8; G6 = 62.3 ± 15.9) (p = 0.33). The smallest value occured when the repair was performed with silane and silorane-based based and stored into ethanol (G10 = 29.9 ± 12.4). The storage media had little influence on the results. Conclusion: The silorane-based resin composite was not effective for repair of the methacrylatebased material.

Introduction The long-term durability of resin composite restorations is a constant worry ��������� [9, 20]��. ������������ Invariably, the replacement of a restoration results in greater weariness of the tooth structure [13]������������������� ����������������������� . For this reason, the restoration repair is a more conservative, faster, and a lower cost procedure both for the professional and the patient.

The study of the physical-chemical and mechanical properties of the adhesive systems should not only be studied between tooth structure and restorative material, but also between two dental materials.

If the adhesive bonding between an old and new resin is effective, the restoration repair becomes a treatment option to be recommended [21]� �����.

In studies evaluating the bond strength of repairs of resin composites, the surface grinding followed by the application of silane bonding agents have demonstrated good results [10]�� ������.

Notwithstanding, this studies have been conducted on resins with the same organic matrix.

In the last decade, a resin with a new siloranebased monomer has been described, which is the result of a reaction between oxirane and siloxane molecules [22]�� ������. ����������������������������������� In this new system, the opening of the oxirane ring during the polymerization reaction compensates the stresses generated during the polymerization contraction. Studies have reported on this new technology. Eick et al. [8] described the hydrophobicity of the material, resulting in stability under oral fluids. A smaller amount of Streptoccocus has also been found on this new resin ��������������������������������������������� [5]������������������������������������������ , therefore favoring the longevity of the material. Additionally, a good color stability ��������� [6, 11]��, bonding values similar for enamel and dentine has been reported ������������������������������������� [12]��������������������������������� . Therefore, this material seems to be promising for restoration of posterior teeth.

However, data on the bonding of this material on methacrylate-based resins still lack in the literature.

Thus, during the repair of silorane-based repair,

it is not clarified which would be the effectiveness and best surface treatment to provide an adequate bonding between the old restoration and new silorane-based resin repair.

Moreover, the behavior of the interaction among the layers should be evaluated at long term. This aging can be simulated laboratorially through storage of the specimens into aqueous solutions.

Normally, the immersion into water at 37ºC is the medium of choice. However, the ethanol solutions well known as aging solutions for BisGMA-based materials can accelerate the material degradation because they can diffuse through the resin provoking its softening ���������������������������������������� [3]������������������������������������� . Thus, the aim of this study was to evaluate the shear bond strength of methacrylateand silorane-based resin composites through using different surface treatments and storage media.

Material and methods Eighty flat bases made with acrylic resin were prepared containing a cylindrical orifice of 6 mm of diameter and 2 mm of deepness. These orifices were filled with a methacrylate-based resin (Filtek Z350 XT, 3M ESPE, St. Paul, USA). Of the 80 resin composite bases, 64 were immersed into distilled water at 37ºC for one week.

The resin composite insertion was executed with a resin spatula at two increments. Each layer was light-cured through a device (Elipar Trilight – Espe - 500mv/cm2) for the period recommended by the manufacturer. This same device was employed during all study phases and the irradiance was checked with a radiometer linked to the light-curing device prior to each use. To adapt the last resin composite increment, a polyester strip (TDV Dental Ltda., Pomerode, Brazil), was placed aiming to leave the surface as flat as possible. The 80 surfaces of resin composite were divided into 10 groups (n = 8). The experimental treatments were executed on the resin composite surface. ���� The groups were divided as follows��:

242 – RSBO. 2013 Jul-Sep;10(3):240-4 Cunha� et al. – ������������� Influence of ������������������������������������������ different surface treatments on the shear ������������������� bond strength of a methacrylate ����������������������������� resin composite repaired with silorane-based resin

• G1 – Control group: immediately after the construction of a flat resin composite base onto the acrylic resin matrix, only one cylinder of Filtek Z350 XT (3.5 mm of diameter per 2 mm of height) was executed onto the resin composite surface with the aid of Teflon matrix. Following, the specimens were stored into distilled water at 37����������� °���������� C for one week. After the construction, the specimens were immersed into distilled water at 37oC for 24 h, prior to the shear bond strength test; • G2: the resin composite surface was grinded with the aid of a medium grit sandpaper (Sof Lex Pop-on, 3M Espe, St. Paul, USA), washed with water jet for 15 s and dried with air jet for 20 s at 10 cm of distance. Next, the adhesive agent (Adper Single Bond 2, 3M Espe, St. Paul, USA) was applied according to the manufacturer’s instructions. With the aid of a Teflon matrix, a cylinder of Filtek Z350 XT resin composite was constructed (3.5 mm of diameter per 2 mm of height). After the construction, the specimens were immersed into distilled water at 37oC for 24 h; • G3: same treatment of G2, however, Filtek P90 adhesive system (3M Espe, St. Paul, USA) and Filtek P90 silorane-based resin composite (3M Espe, St. Paul, USA) were used. After the construction, the specimens were immersed into distilled water at 37oC for 24 h;

• G4: the surface was grinded with medium grit sandpaper, washed with water jet for 15 s and dried with air jets for 20 s at 10 cm of distance.

Following, a silane (Silano, Ângelus, Londrina, Brazil) and Single Bond 2 adhesive agent were applied and a cylinder of Filtek Z350 XT resin composite was constructed. After the construction, the specimens were immersed into distilled water at 37oC for 24 h; • G5: same treatment of G4, however the Filtek P90 adhesive system and Filtek P90 silorane-based resin composite was used. Then, the specimens were immersed into distilled water at 37o C for 24 h; • G6, G7, G8, G9 e G10: same treatments of G1, G2, G3, G4 and G5, respectively; however, after the construction of the resin composite cylinders, the specimens were kept into ethanol (75% in volume) at 37oC for 24 hours, to mimic the resin composite aging. After the storage period in either water or ethanol, the specimens were submitted to shear bond strength test in a universal testing machine (EMIC, São José dos Pinhais – PR, Brazil), with crosshead speed of 1.0 mm/min.

Data were analyzed through one-way ANOVA. The possible statistical differences among groups were determined by Tukey test. A global level of significance of 5% was adopted.

Results The means (in MPa) and standard deviations of the results obtained are seen in table I. There were statistically significant differences among the treatments proposed (p < 0.001). Only the repairs executed with silane and Z350 XT (G4 = 46.2 ± 12.9; G9 = 48.1 ± 16.3) were capable of generating values similar to those of controls (G1 = 59.2 ± 15.8; G6 = 62.3 ± 15.9) (p = 0.33). None repair performed with siloranebased resin generated shear bond strength values similar to those of control group. The smallest value was obtained when the repair was carried out with the silorane-based resin after the application of a silane and storage in ethanol (G10 = 29.9 ± 12.4). Generally, the storage media had a little influence on the results.

Table I – Means (in MPa) and standard deviations for the experimental conditions tested

Storage

Water

Ethanol

Group

Treatment

MPa

G1

Control

59.1 ± 15.8

bc

G2

Grinding, water, air, adhesive, Filtek Z350 XT resin

33.6 ± 13.5

a

G3

Grinding, water, air, adhesive, Filtek P90 resin

40.4 ± 8.9

G4

Grinding, water, air, silane, adhesive, Filtek Z350 XT resin

46.1 ± 12.8 abc

G5

Grinding, water, air, silane, adhesive, Filtek P90 resin

36.0 ± 15.8

a

G6

Control

62.3 ± 15.8

c

G7

Grinding, water, air, adhesive, Filtek Z350 XT resin

36.7 ± 15.8

a

G8

Grinding, water, air, adhesive, Filtek P90 resin

32.9 ± 11.1

a

G9

Grinding, water, air, silane, adhesive, Filtek Z350 XT resin

G10

Grinding, water, air, silane, adhesive, Filtek P90 resin

Different superscript letters mean statistically significant differences (p < 0.05)

ab

48.1 ± 16.2 29.8 ± 12.4

abc a

243 – RSBO. 2013 Jul-Sep;10(3):240-4 Cunha� et al. – ������������� Influence of ������������������������������������������ different surface treatments on the shear ������������������� bond strength of a methacrylate ����������������������������� resin composite repaired with silorane-based resin

Discussion Silorane-based resins have been recently launched worldwide. Magni et al. [16] evaluated the repair with silorane-based resin onto another silorane-based resin. ������������� Accordingly, ��������� Ivanovas et al.

[14], Lurhs et al. ������������������ [15] and Maneenut et al. [17] studied the silorane-based repair and verified that it is possible to execute a methacrylate-based resin repair onto a silorane-based resin. However, information on silorane-based resin repair onto methacrylate-based resin is still scarce. The idea of repairing a methacrylate-based resin with a silorane-based resin is justified because not always the professional knows the resin type that was employed to construct a prior restoration. This aspect was recently studied by Popoff et al. [18]. ������ In a clinical study with one year of following-up, these authors observed that the silorane-based resin used to repair a methacrylate-based resin behaved similarly to control group, in which the repair was executed with a methacrylate-based resin. In this present study, however, none repair performed with silorane-based resin generated bond strength values similar to those of control group. Maybe the evaluation time of one year employed in the study of Popoff et al. [18] had not been enough to detect a possible clinical difference.

Different methods can measure the bond strength to determine either the effectiveness or the ineffectiveness of the adhesion between different materials, such as microtensile, microshear or shear bond strength. In this present study, the shear bond strength method was used to measure the adhesive forces between aged methacrylatebased resin simulating a restoration and a new methacrylate- or silorane-based resin. This type of test has the advantage to mimic the clinical condition very closely because it results in stress on the interface between the materials [1]�� �����.

The most commonly and traditionally technique for in vitro aging of specimens is the storage in water for longer times ����������������������������������� [7]�������������������������������� . This decrease in the adhesive effectiveness is caused by the hydrolysis degradation of the organic components present in the adhesive interface. Notwithstanding, another simulated aging method is storage in ethanol, as used by Asmussen [1] and Furuse et al. ������������������������������� [10]. ������������������������� The different methods of aging are employed attempting to estimate which would be a possible clinical behavior at long term.

In this present study, there were no differences between water and ethanol storage. It is important to highlight that the specimens were aged in ethanol for only 24 h and that longer times could have influence on the results.

The different treatments influence on the bond strength of the different groups. The chemical treatment of the resin composite prior to the construction of the repairs by applying silanizing agents is controversy according to the studies conducted by Soderholm et al. [19], ������������ Brosh et al. [4] and Furuse et al. [10]. ��������������������������������� In this present study, the shear bond strength values of the silanized groups with silorane-based repairs were smaller; however, there were no statistical significant differences in relation to the groups in which the silane agent was not applied.

It is important to emphasize that only one type of methacrylate-based resin was used in this present study and that not all materials are similar. Thus, the data here presented should be cautiously interpreted.

Further studies evaluating different methacrylatebased resins as well as different types and methods of silane application should be conducted.

Conclusion Taking into consideration the limitations of this present study, it can be concluded that the repair of methacrylate-based resin with siloranebased resin demonstrated the smallest shear bond strength values.

References 1. Anusavice KJ. Phillips materiais dentários. 10. ed. Rio de Janeiro: Guanabara Koogan; 1998.

2. Asmussen E. Softening of BISGMA-based polymers by ethanol and by organic acids of plaque.

Scand J Dent Res. 1984 Jun;92(3):257-61.

3. Benetti AR, Asmussen E, Munksgaard EC, Dewaele M, Peutzfeldt A, Leloup G et al. Softening and elution of monomers in ethanol. Dent Mater.

2009 Aug;25(8):1007-13.

4. Brosh T, Pilo R, Bichacho N, Blutstein R. Effect of combinations of surface treatments and bonding agents on the bond strength of repaired composites.

J Prosthet Dent. 1997 Feb;77(2):122-6.

5. Buergers R, Schneider-Brachert W, Hahnel S, Rosentritt M, Handel G. Streptococcal adhesion to novel low-shrink silorane-based restorative. Dent Mater. 2009 Feb;25(2):269-75.

6. Cunha LF, Santana L, Baratto SSP, Mondelli J, Haragushiku GA, Gonzaga CC et al. Staining susceptibility of methacrilate and silorane-based materials: influence of resin type and storage time.

RSBO. 2013 Apr-Jun;10(2):161-6.

244 – RSBO. 2013 Jul-Sep;10(3):240-4 Cunha� et al. – ������������� Influence of ������������������������������������������ different surface treatments on the shear ������������������� bond strength of a methacrylate ����������������������������� resin composite repaired with silorane-based resin

7. De Munck J, Van Landuyt K, Peumans M, Poitevin A, Lambrechts P, Braem M et al. A critical review of the durability of adhesion to tooth tissue: methods and results. J Dent Res. 2005 Feb;84(2):118-32.

8. Eick JD, Smith RE, Pinzino CS, Kostoryz EL. Stability of silorane dental monomers in aqueous systems. J Dent. 2006 Jul;34(6):405-10.

9. Ergucu Z, Turkun LS. Clinical performance of novel resin composites in posterior teeth: 18-month results. J Adhes Dent. 2007 Apr;9(2):209-16.

10. Furuse AY, Cunha LF, Benetti AR, Mondelli J. Bond strength of resin-resin interfaces contaminated with saliva and submitted to different surface treatments. J Appl Oral Sci. 2007 Dec;15(6):501-5.

11. Furuse AY, Gordon K, Rodrigues FP, Silikas N, Watts DC. Colour-stability and gloss-retention of silorane and dimethacrylate composites with accelerated aging. J Dent. 2008 Nov;36(11):945-52.

12. Garcia RN, Alvarez AEG, Dias CE, Mazaro MA, Firmo T, Stuker H et al. Bond strength of contemporary restorative systems to enamel and dentin. RSBO. 2011;8(1):54-60.

15. Luhrs AK, Gormann B, Jacker-Guhr S, Geurtsen W. Repairability of dental siloranes in vitro. Dent Mater. 2011 Feb;27(2):144-9.

16. Magni E, Ferrari M, Papacchini F, Hickel R, Ilie N. Influence of ozone application on the repair strength of silorane-based and ormocer-based composites. Am J Dent. 2010 Oct;23(5):260-4.

17. Maneenut C, Sakoolnamarka R, Tyas MJ. The repair potential of resin composite materials. Dent Mater. 2011 Feb;27(2):e20-7.

18. Popoff D, Rosa TS, Ferreira R, Magalhaes C, Moreira A, Mjor I. Repair of dimethacrylatebased composite restorations by a silorane-based composite: a one-year randomized clinical trial.

Oper Dent. 2012 Sep-Oct;37(5):E1-E10.

19. Soderholm KJ, Zigan M, Ragan M, Fischlschweiger W, Bergman M. Hydrolytic degradation of dental composites. J Dent Res. 1984 Oct;63(10):1248-54.

20. Turkun LS, Turkun M, Ozata F. Clinical performance of a packable resin composite for a period of 3 years. Quintessence Int. 2005 May;36(5):365-72.

13. Gordan VV. Clinical evaluation of replacement of class V resin based composite restorations. J Dent. 2001 Sep;29(7):485-8.

21. Vankerckhoven H, Lambrechts P, van Beylen M, Davidson CL, Vanherle G. Unreacted methacrylate groups on the surfaces of composite resins. J Dent Res. 1982 Jun;61(6):791-5.

14. Ivanovas S, Hickel R, Ilie N. How to repair fillings made by silorane-based composites. Clin Oral Investig. 2011 Dec;15(6):915-22.

22. Weinmann W, Thalacker C, Guggenberger R. Siloranes in dental composites. Dent Mater. 2005 Jan;21(1):68-74.

ISSN: Electronic version: 1984-5685 RSBO. 2013 Jul-Sep;10(3):245-51

Original Research Article

DMFT index of 12 year-old students of public schools participating in the Project of Education for Working for Health Denise Vizzotto1 Helena Maria Antunes Paiano1 Ana Caroline Rudey1 Andréia Karina Lovera1 Pricylla Hagemann1 Tatiane Gazolla1 Corresponding author: Denise Vizzotto Rua Eduardo Miers, n. 102, apto. 504 – Atiradores CEP 89203083 – Joinville – SC – Brasil E-mail: dvizzotto@brturbo.com.br ¹ Department of Dentistry, University of Joinville Region – Joinville – SC – Brazil.

Received for publication: December 19, 2012. Accepted for publication: February 25, 2013.

Keywords: DMFT index; dental caries; epidemiological surveys; oral health.

Abstract Introduction: Epidemiological surveys provide a key basis for assessing current and future oral health care needs of a population by yielding reliable data for designing national or regional health programs [12]. Objective: To assess the oral health status of 12-yearold adolescents by applying DMFT index in the city of Joinville, SC, who took part in the PEW Health Project 2010-2011 and designing a comparative study between 2003 and 2010 national, state, municipal and other DMFT surveys for this same age range. Material and methods: Analytical cross-sectional observational study. Dental health assessment tool used was DMFT and deft index. The codes and criteria used for the survey used the tooth as a study unit according to methodology proposed by WHO and reported in the SB-Brazil Assessor’s Manual [3]. Sample size was 194 students attending public junior high school. Chi-square test for qualitative variables and Student’s t test for quantitative variables were used, with two-tailed significance level of 5%. Results: DMFT was 0.84, standard deviation 1.31 and confidence interval 0.65 (lowest) and 1.02 (highest). Rate of cavity-free children or zero DMFT was 58.8%,

246 – RSBO. 2013 Jul-Sep;10(3):245-51 Vizzotto� et al. – ����� DMFT index ������ of ��� 12 ��� year-old ��������������������� students of public ����������������������������� schools participating in ������� the Project ����������� of Education �������������� for Working �������� for ���� Health ������

a total of 114 children. Conclusion: The students of the city of Joinville, SC assessed by this study showed low cavity prevalence, thereby reaching WHO approved targets for 2010.

Introduction The knowledge of the health or disease condition of a population is fundamental for establishing a health working planing. In Brazil, the Law #8,080 of September 19 of 1990, known as Organic Health Law claims (Article 7th, VII) “the use of epidemiology for the establishment of priorities, allocation of resources and programmatic guidance” [14, 19].

The epidemiolog ica l sur veys prov ide a n important basis for the estimative of both the current situation and the further necessity of health care of a population, resulting in reliable data for the development of either national or regional health programs. The main index for epidemiological surveys in oral health has been DMFT (decayed, missed, and filled teeth) [12].

The World Health Organization (WHO) uses the mean DMFT index at 12 years-old as the basic index of comparison for oral health of different populations.

This index is of easy collection in primary schools, so that DMFT for this age group has been the best epidemiological index to describe the oral health status of the childhood and adolescence [14].

The caries attack rate, was originally created by Klein and Palmer in 1937, known by the acronym DMF and it is still the most used index worldwide, being kept as the basic landmark for the diagnosis of dental conditions, preparation and assessment of Oral Health Programs. The caries attack rate (DMFT) has been applied to permanent teeth. For primary teeth, the index is identified by lowercase letters, so-called deft index, which uses criteria similar to those of DMFT [12, 17]. The sampling method, used in DMFT, it is a stratified technique, aiming to include the most important population subgroups regarding to the different levels of the disease and comprise a standardized number of individuals of determined age groups at each site [12].

According to WHO [23], there are five severity stages for DMFT at 12 years-old: very low (from 0 to 1.1), low (from 1.2 to 2.6), moderate (from 2.7 to 4.4), severe (from 4.5 to 6.5), very severe (6.6 or higher).

In the first Brazilian epidemiological study, conducted in 1986 by the Ministry of Health, at 12 years-old, it was detected that tooth caries reached a DMFT index of 6.7, with prevalence higher than 90% [1].

WHO advocated for the 2000s a mean DMFT of 3.0 at 12 years-old, that is, at most three teeth injured by the disease; for the 2010s a mean DMFT of at most one tooth injured by the disease [8]. The survey conducted in 2010 by the Brazilian Ministry of Health (SB Brazil 2010) [4], comprised 177 Brazilian cities, 26 state capitals, and the Federal District as well as 30 cities randomly selected for each one of the five regions of the country. In 2003, at 12 yearsold, the disease reached 69% of the population, decreasing to 56% in 2010. This decrease of 13 percentage points corresponds to a decrease of 19% in the disease prevalence. The mean number of teeth damaged by the disease also decreased at 12 years-old: from a DMFT index of 2.8 in 2003 to 2.1 in 2010, a reduction of 25%. The proportion of caries-free children at 12 years-old increased from 31% to 44% [4]. The city of Joinville (SC) was enrolled in the sample of the 2003 survey and the DMFT index found at 12 years-old was 1.19 [20].

The purpose of this study was two-fold: to assess the diagnosis of the oral health condition of adolescents at 12 years-old, through DMFT index, attending public junior high schools of the city of Joinville (SC) participating in the Project of Education for Working for Health 2010/2011 (PEWHealth); and to elaborate a comparative study among the Brazilian national, state, and municipal DMFT index of 2003 and 2010 as well as other studies at this age range.

Material and methods Analytical cross-sectional observational study.

Dental health assessment tool used was DMFT and deft index. The codes and criteria used for the survey used the tooth as a study unit according to methodology proposed by WHO and reported in the SB-Brazil Assessor’s Manual [3].

The survey was conducted in the following four public junior high school: “Rosa Maria Berezoski Demarchi” (Paraíso district), “Pauline Parucker” (Boehmerwaldt district), “Hilda Ana Krischs” (Iririú district) and “Lacy Luíza Flores” (Itinga district), located in the suburbs of the city of Joinville (SC). The choice for the districts and schools was determined by the social-economic status presented by the students and the location in the areas enrolled

247 – RSBO. 2013 Jul-Sep;10(3):245-51 Vizzotto� et al. – ����� DMFT ������ index ��� of ��� 12 ��������������������� year-old students of ����������������������������� public schools participating ������� in the ����������� Project of �������������� Education for �������� Working ���� for ������ Health

in the Family Health Teams of the PEW-Health of 2010/2011, respectively. The mean income of the parents/legal guardians per home and district was R$ 400.00; R$ 500.00; R$ 600.00 and R$ 480.00, respectively [7].

The sample was composed by 194 students of 12 years-old, 11 months and 29 days up to the moment of the data collection, regardless of the gender, race and social class. The sampling was randomly obtained. Exclusion criteria comprised students aging above the age range; using orthodontic appliance at the moment of the examination and/ or whose parents/legal guardians did not sign the consent form. Prior to the examinations, oral hygiene through toothbrushing and toothpaste was executed in all students selected for the research. The examinations were carried out only after the signing of a clarified consent form by the parents and/or legal guardians (Ethical Committee in Research protocol number #115/2011). The data collection followed the methodology proposed by the Brazilian Health Ministry: outdoors in a bright environment through using disposable tongue depressors; plane dental mirror and WHO dental probe.

The collection instrument used was a structured questionnaire, available at the Brazilian Ministry website [3], and adapted following the requirements of this study. Only the blanks corresponding to the general information (number identity of the student, age in years, gender, race, date of examination) and the blanks regarding to Dental Caries and Treatment Needs were filled in using the codes proposed by the Brazilian Ministry of Health.

Fo u r e x a m i n e r s , fo u r a n n o t a t o r s a n d two assistants participated in data collection (undergraduate students of the School of Dentistry of the Joinville Region - Univille). Inter- and intraexaminer agreement calibration was performed according to the methodology proposed [3], obtaining a general minimum percentage of agreement of 0.988% and minimum weighted kappa of 0.778.

Data were stored in MsExcel 2003 software.

Descriptive tables were constructed and the statistical tests applied were Chi-square to compare the qualitative variables and Student’s t test for quantitative variables with two-tailed level of significance of 5%.

Results The number of students in the four public students during the period of the study and in the age range was 611. Two-hundred and seventy-one students were randomly drawn to compose the sample. However, 194 students at 12 years-old were, in fact, examined. Of these, 100 (51.5%) were male and 94 (48.45%) female. Concerning to race, 108 students identified themselves as Caucasian, (representing more than 50% of the sample), Brown (35.05%), Black (6.19%), Yellow (2.06%) and Indian (1.03%).

The DMFT mean found was of 0.84 (SD = 1.31), confidence interval of 0.65 (minimum) and 1.02 (maximum). The percentage of caries-free children (DMFT = 0) was of 58.8%, corresponding to 114 children. The caries prevalence was of 23%, without statistically significant differences between genders (male = 23%; female = 22.3%) (p = 0.91 – Chi-square test of independence). There were no statistically significant differences between genders for general sample DMFT (p = 0.07 for male and p = 0.88 for females – Student’s t test).

Concerning to the DMFT composition – decayed, missed, and filled – all components showed similar proportions between genders (table I). Statistically, there were no differences of mean DMFT values between genders.

Table I – DMFT mean and components means per gender. Joinville, 2011

Variables

Male

Female

Total

100 (51.5%)

94 (48.4%)

194

Decayed

36 (1.4%)

41 (1.6%)

77

Missed

0

2 (0.08%)

2

Filled

31 (1.2%)

52 (2.1%)

83

DMFT

0.67

1.01

0.84

Confidence interval

(0.45;0.89)

(0.71;1.31)

(0.65;1.02)

Standard deviation

1.12

1.47

1.31

Source: Primary

248 – RSBO. 2013 Jul-Sep;10(3):245-51 Vizzotto� et al. – ����� DMFT ������ index ��� of ��� 12 ��������������������� year-old students of ����������������������������� public schools participating ������� in the ����������� Project of �������������� Education for �������� Working ���� for ������ Health

For children with traumatized teeth, the percentage was of 10.3%, which corresponded to 20 children with a total of 42 (0.8%) traumatized teeth, while 29.4% of the population studied required the treatment of one or more teeth.

Discussion Between the 1960s and 70s, the tooth caries rates exhibited high values at 12 years-old in developed and some developing countries. In the last years, the disease decrease at this age has been observed in Brazil and worldwide [18].

T h i s pre s ent st udy cor rob orate s t he s e affirmations, because the DMFT found in the population researched was of 0.84, which is considered of very low prevalence, according to the measurement scale of caries attack severity at 12 years-old advocated by WHO [23].

Traebert et al. [21] studied a student population from the city of Blumenau (SC/Brazil). A sample of 1,473 students participated in the survey, representing four strata: 6-12 year-old students from public a nd private schools. The caries prevalence in the permanent dentition at 12 yearsold was of 54.7%, and DMTF index was of 1.46 for public schools. In the public schools, at this same age, it could be seen that 53.0% of children did not exhibit treatment requirements. Cypriano et al. [6] examined 3,731 children from 5 to 12 years-old and found tooth caries data in seven cities of the region of Sorocaba (São Paulo/Brazil) which had or did not have f luoridation of the public water supply. At 12 years-old, 32.3% of the students were caries free and the DMFT was of 2.6. The children living in fluoridated areas had the smallest caries experience in primary dentition; also, these areas showed a higher percentage of caries free children, denoting the best conditions of oral health in these cities. Such data are different from those of this present study.

Freire et al. [9] conducted a study aiming to compare 12-year-old students from private and public study regarding to the caries prevalence, periodontal status, dentofacial anomalies, and fluorosis. This was a cross-sectional study with 1,947 12-year-old students enrolled in urban area of the city of Goiânia (Goiás/Brazil), divided into 1,790 children from public and 157 from private

schools, in 2003. Most of the students examined were female (51.6%), and the caries prevalence was of 64% and the mean DMFT was of 2.29.

The components decayed, missed, and filled comprised 49.6%, 2.1% and 48.2% of the index, respectively. The students from public schools showed the highest prevalence of the disease and highest values of both DMFT and its components than those of the private schools.

The SB Brazil 2003 epidemiological survey, conducted by the Brazilian Health Ministry [2], found a Brazilian DMFT of 2.78 at 12 years-old, value similar to that of the Brazilian South region (2.31); that of the study of Freire et al. [9] for the city of Goiânia, (Goiás/Brazil), in 2003; and that of the study of Cypriano et al. [6] for seven cities of the area of Sorocaba (São Paulo/Brazil), whose mean DMFT values were 2.29 and 2.6, respectively. However, this value was far above the mean of 1.19 found for the city of Joinville in 2003 [20] and of 1.46 reported in the study of Traebert et al. [21] in public schools of the city of Blumenau �������������� (SC). ����� In the SB Brazil 2010 epidemiological survey [4], DMFT at 12 years-old was of 2.1, value similar to that found in the countryside of the Brazilian South region (2.17). The same data for the capitals of Curitiba and Porto Alegre was of 1.53 e 1.49, respectively. Notwithstanding, the same study found a mean of 0.77 for the city of Florianópolis, which was similar to that found in the city of Joinville (2011) by this present study.

The DMFT means found in SB Brazil 2010 [4] for the Brazilian South (2.06) and Southeast regions (1.72) were similar between each other, although higher than that of this present study (0.84). For the Brazilian North (3.16), Northeast and Midwest regions (2.63), the DMFT mean was very higher than those of the other regions and that of this present study.

The data of table II demonstrated a reduction of t he DMF T index from 2.78 to 2.1, which corresponds to 26%, when compared to those of the Brazilian epidemiological surveys of 2003 and 2010 [4]. This reduction could also be observed for the city of Joinville, whose DMFT mean changed from 1.19 in 2003 to 0.84 in 2011, resulting in a reduction of 30%.

249 – RSBO. 2013 Jul-Sep;10(3):245-51 Vizzotto� et al. – ����� DMFT ������ index ��� of ��� 12 ��������������������� year-old students of ����������������������������� public schools participating ������� in the ����������� Project of �������������� Education for �������� Working ���� for ������ Health

Table II – Comparison among the DMFT index and Brazilian caries prevalence of the epidemiological surveys of 2003-2010 of the South region and its capital and the DMFT found in the study in Joinville, 2011

Variables

DMFT/2003*

Prevalence

DMFT /2010

Prevalence

Brazil

2.78

Moderate

2.1

Low

South Region

2.31

Low

2.1 (countryside)*

Low

Curitiba

–

–

1.53

Low

Porto Alegre

–

–

1.49

Low

Florianópolis

–

–

0.77

Very low

1.19

Low

0.84

Very low

Joinville

* In 2003, the survey conducted by the Ministry of Health showed results only for Brazil and its geographical region . In 2010, the results for Brazil, its capitals and countryside of the geographical regions Source: Primary

Still regarding the caries-free children (DMFT = 0), this study found a value of 58.8%, which was similar to that found in the city of Florianópolis (68.4%), reported in the SB Brazil 2010 epidemiological survey [4], and higher than that found in the capital of the South Region: Porto Alegre (48.8%) and Curitiba (44.7%), and that found in the countryside of the South Region (39.7%). There were no statistically differences between the results of Joinville in 2011 and of Florianópolis in 2010 (p = 0.76 –Student’s t test). However, there were statistically significant differences in relation of the other results (p < 0.005 – Student’s t test).

Concerning to the DMFT components, this study found 22.7% for “D” (decayed), which was very below the results reported by SB Brazil [4] for all country (54.1%), countryside of the South Region (55.3%) and for Florianópolis (59.7%), as seen in table III. Table III – Comparison between the DMFT mean and the ratio of its components in relation to total DMFT, according to the data of SB Brazil 2010 and Joinville 2011

Variables

% Decayed

% Missed

% Filled

DMFT

Brazil

54.1

5.8

35.3

2.06

Countryside of South Region

55.3

1.8

36.4

2.17

Florianópolis

59.7

1.3

37.7

0.77

Joinville

22.7

1.0

26.8

0.84

Source: Primary

For the M component (missed), the study found a value of 1.0%, which was lower than those reported in the SB Brazil 2010 epidemiological survey [4] for Brazil (5.8%), countryside of the South Region (1.8%) and Florianópolis (1.3%).

Concerning to F component (filled), the present study found a value of 26.8%, which was different from those of the SB Brazil 2010 epidemiological survey for Brazil (35.3%), countryside of the South Region (36.4%) and Florianópolis (37.4%) [4]. It could be inferred that the result found in the study of Joinville is in agreement with the percentage of decayed teeth, which was lower than those of the other areas, as previously cited. Still, the study identified that 70.6% of the adolescents did not required any treatment.

The prevalence of caries in the city of Joinville, considering the sample studied, exhibits a decrease similar to that found by the Brazilian Ministry of Health at 12 years-old. The mean DMFT value decreased from 1.19 to 0.84, exhibiting a reduction of 30%, while this same index showed a reduction of 26% for all the country. The result confirms the decrease in the caries prevalence at this age range, similarly to which has been happening in the Brazilian South and Southeast Regions, and demonstrated by the epidemiological surveys conducted by the Brazilian Ministry of Health in 2003 and 2010 [2, 4].

Pinto [16], Ma rcenes a nd Bonecker [10], Traebert et al. [21] observed that the oral health condition improved in the last decades in Brazil.

250 – RSBO. 2013 Jul-Sep;10(3):245-51 Vizzotto� et al. – ����� DMFT ������ index ��� of ��� 12 ��������������������� year-old students of ����������������������������� public schools participating ������� in the ����������� Project of �������������� Education for �������� Working ���� for ������ Health

The authors cited as possible causes for this decrease: the addition of fluoride to public water supply, the large use of fluoride dentifrices and the changes in the health services which accompanied the implementation of the Brazilian Unified Health System. Other important causes would be, in some countries, the consumption of sugar and the improvement in the life conditions of the population [10, 16, 21]. The results found by the survey in Joinville demonstrated the decrease in the caries rates, confirming the findings in the aforementioned studies.

According to SB Brazil epidemiological survey [2], at 12 years-old, there are marked differences between the cities with and without water supply fluoridation. Joinville is a fluoridated city since 1979, so that 12-year-old children have already been receiving fluoride since their birth.

Conclusion The 12-year-old students of the city of Joinville (SC) evaluated by this study exhibited a low prevalence of caries, reaching the rate advocated by WHO for 2010 [8], fact that indicates that preventive and oral health promotion measurements for this age range are right on target. Other oral health epidemiological surveys should be conducted to monitor the epidemiological profile of this population.

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6. Cypriano S, Pecharki GD, Sousa MLR, Wada RS. A saúde bucal de escolares residentes em locais com ou sem fluoretação nas águas de abastecimento público na região de Sorocaba, São Paulo, Brasil.

Cad Saúde Pública. 2003;19:1063-71.

7. Diagnóstico Social da Criança e do Adolescente de Joinville. ������������������������������������� [cited 2011 Oct 20]. Available from: URL:http://www.criancaeadolescentejlle.org/ind_ ugs.html.

8. Frazão P. Epidemiologia em saúde bucal. In: Pereira AC (Org.). Odontologia em saúde coletiva: planejando ações e promovendo saúde. Porto Alegre: Artmed; 2003. p. 64-82.

9. Freire MCM, Reis SCGB, Gonçalves MM, Balbo PL, Leles CR. Condição de saúde bucal em escolares de 12 anos de escolas públicas e privadas de Goiânia, Brasil. Rev Panam Salud Publica.

2010;28(2):86-91.

10. Marcenes W, Bonecker MJS. Aspectos epidemiológicos e sociais das doenças bucais. In: Buischi YP (Org.). Promoção de saúde bucal na clínica odontológica. São Paulo: Artes Médicas; 2000. p. 75-98.

11. Nadanovsky P. O declínio da cárie. In: Pinto VG (Org.). Saúde bucal coletiva. São Paulo: Santos; 2000. p. 341-51.

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13. Organização Mundial de Saúde. Levantamentos básicos em saúde bucal. 4. ed. São Paulo: Santos; 1999.

14. Pereira AC. Odontologia em saúde coletiva: planejando ações e promovendo saúde. Porto Alegre: Artmed; 2003. Cap. IV. 15. Pinto VG. Saúde bucal: panorama internacional.

Ministério da Saúde. Secretaria Nacional de Programas Especiais de Saúde. Divisão Nacional de Saúde Bucal. Brasília; 1990.

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251 – RSBO. 2013 Jul-Sep;10(3):245-51 Vizzotto� et al. – ����� DMFT ������ index ��� of ��� 12 ��������������������� year-old students of ����������������������������� public schools participating ������� in the ����������� Project of �������������� Education for �������� Working ���� for ������ Health

17. Pinto VG. Epidemiologia das doenças bucais no Brasil. In: Kriger L (Org.). Promoção de saúde bucal. São Paulo: Artes Médicas; 1997. p. 24-41.

18. Pinto VG. Saúde bucal coletiva. 4. ed. São Paulo: Santos; 2000. p. 341-51.

19. Rouquayrol MZ. Epidemiologia e saúde. 4. ed.

São Paulo: Medsi; 1994.

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Relatório do Levantamento Epidemiológico SB Brasil 2003. Joinville; 2003.

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ISSN: Electronic version: 1984-5685 RSBO. 2013 Jul-Sep;10(3):252-6

Original Research Article

Ligature-induced periodontitis associated to alcohol using and stress on animal’s behavior: study in rats Tereza Aparecida Delle Vedove Semenoff¹ Álvaro Henrique Borges¹ Alessandra Nogueira Porto1 Fabio Luis Miranda Pedro¹ Igor Francisco Arruda de Abreu² Natalino Francisco da Silva³ Alex Semenoff Segundo¹ Corresponding author: Alex Semenoff Segundo Rua Profa. Azélia de Melo, n. 318, apto. 63, B. Araés CEP 78005-700 – Cuiabá – MT – Brasil E-mail: semenoff@uol.com.br ¹ Professor of the Master in Integrated Dentistry, University of Cuiabá, Faculty of Dentistry – Cuiabá – MT – Brazil. ² Dentist. Trainee in the Discipline of Hospital Dentistry, University of Cuiabá – Cuiabá – MT – Brazil. ³ Undergraduate student in Biology, University of Cuiabá – Cuiabá – MT – Brazil.

Received for publication: December 20, 2012. Accepted for publication: February 26, 2013.

Keywords: alcoholism; physiological stress; Periodontics; rats.

Abstract Introduction and Objective: To evaluate the effect of ligature-induced periodontitis association with chronic use of alcohol and stress on the behavior of the animals. Material and methods: Forty female rats were distributed equally into the following groups: control (CG), alcohol+stress+ligature (ASLG), stress+ligature (SLG), alcohol+ligature (ALG), ligature (LG). In the first day, the animals of ALG and ASLG were exposed to the ingestion of water and 20% alcohol solution (v/v). The animals of ASLG and SLG underwent stress testing through physical restraint for 4 daily hours, during 60 days until their euthanasia. In the next day after the beginning of the research, the animals of ALG, ASLG, SLG and LG were submitted to ligature installation around the right maxillary second molar. The evaluation of the behavior of the animals was executed through open field variables (amount of central and peripheral segments flown, times in which the animal was kept on two paws without support, self-cleaning movement - itchy nose)

253 – RSBO. 2013 Jul-Sep;10(3):252-6 Semenoff� et al. – ������������������������������� Ligature-induced periodontitis �������������� associated to alcohol �������������� using �������������� and stress on ��������� animal’s ���������������� behavior: study ������� in rats

and maze cross parameters (amount of entrances in the arms and time of permanence in these sites). Data were gathered, their means calculated and submitted to analysis of variance and Ducan, KruskalWallis and Mann-Whitney tests (p < 0.05). Results: The results did not demonstrate statistical differences for the parameters analyzed, except from the closed filed, in which ASLG and SLG exhibited the longest time of permanence. Conclusion: Considering the methodology used, it was possible to observe that the alcohol associated with chronic stress and ligature-induced periodontitis demonstrated few alterations on the behavior of the animals.

Introduction In many times, the stress of the modern life can be considered an ally in surpassing the challenges of daily life. However, for long periods and at high doses, it can cause irreversible damages to physical and mental health of an individual [3, 16]. The stress has a strict relationship with the immune, nervous and endocrine systems and it can cause from simple body pain to serious, problematic and irreversible conditions such as heart diseases, cancer and autoimmune diseases [3, 11].

Other chemical factor of organic deterioration is alcohol use. In Brazil there have been reports on the increase of the numbers of consumers and the high mortality associated with alcoholism [5].

In an epidemiologic study conducted in Rio de Janeiro, it was possible to observe a prevalence of 51% for alcohol consumption and 3% of addiction to this substance [1]. In Cuiabá, these rates are even greater, because 71% of the young interviewed affirmed they had consumed alcohol and 13.4% seemed to be alcoholics [21].

The oral diseases affect great part of the world population [22]. Periodontitis compromised the quality of life indicators of human beings [12] and it is strictly related to systemic diseases, with high public costs, being considered as a public health problem [2]. It is also important emphasizing the role of the consumption of alcoholic beverages plays in the predisposition of diseases, including oral cancer [24]. Considering the associations among alcoholism, stress and periodontitis, the aim of this study was to evaluate the behavior of the association of alcohol consumption, chronic stress, and oral infection through periodontitis induction in rats.

Material and methods This present study was approved by the Ethical Committee in Research of the General University

Hospital of the University of Cuiabá (Unic), under protocol number #0307-321.

To execute the research, 40 female adult Wistar rats (Rattus novergicus) obtained from the Central Vivarium of Unic were selected. The animals were randomly distributed into five groups, as follows: control group (CG), alcohol associated with ligature group (ALG), alcohol associated with stress and ligature (ASLG), stress associated with ligature (SLG) ligature group (LG).

After the formation of the groups, the animals assigned to both ALG and ASLG ingested 20% ethanol solution (volume/volume) – during the study [19].

All the periodontal disease induction was executed under sedation through intramuscular injection of 0.1 ml of ketamine hydrochloride (Dopalen, Agribrands.

Saúde Animal, Paulínia, SP, Brazil) associated with 0.05 ml de xylazine hydrochloride (Rompun, Bayer.

Saúde Animal, São Paulo, SP, Brazil), per each 100 grams of body weight.

In the first day of the research, the animals assigned to the ALG and ASLG were anesthetized and then submitted to the ligature installation through sterile suture thread number 4-0, (Ethicon, Johnson e Johnson, São Paulo, Brazil) around the right maxillary second molar. After the ligature installation, a period of 60 days was elapsed, and then all groups were submitted to euthanasia through anesthetic excess [20].

The stress induction was performed by physical restraint of the rats assigned to ASLG and SLG during all study. The restraint was induced by the maintenance of the animals inside PVC tubes compatible with their size. This procedure lasted 4 daily hours from 6h to 18h, at mean temperature of 24°C. The period of chronic stress duration was of 59 days, starting from one day after the periodontal disease induction [4].

For this analysis, behavioral tests of maze cross and open field were carried out. The device used in open field was a circular arena with 50 cm of radius, divided by segments in two circles: a central

254 – RSBO. 2013 Jul-Sep;10(3):252-6 Semenoff� et al. – Ligature-induced ������������������������������� periodontitis associated �������������� to alcohol �������������� using and �������������� stress on ��������� animal’s behavior: ���������������� study in ������� rats

one comprising eight equal parts; a peripheral one, with 16 equal parts. The maze cross device was composed of four arms: two opened and two closed.

The closed arms were 30 cm of height, 53 cm of length and 13 cm of width.

After each observation in the respective analysis objects, the devices were cleaned with distilled water.

For the open field analysis, the number of central and peripheral segments flown, times in which the animal was kept on two paws without support, selfcleaning movement - itchy nose were considered as parameters. For the maze cross, the parameters used were the amount of entrances in the arms and time of permanence in these sites [14].

Based on the study results, data were submitted to the analysis of variance and Ducan test, and Kruskal-Wallis with Mann-Whitney test, with level of significance of 5%.

Results Concerning to the variable number of times in open field, ASLG stayed more times than LG

(p < 0.05). There were no statistically significant differences (p > 0.05) among CG, SLG and ALG. For the variable number of times in closed field, ASLG was the most frequent group (p < 0.05).

CG, SLG, ALG and LG did not exhibit statistically significant differences among each other (p > 0.05). In maze cross device, the variables times of permanence in open and closed field did not evidence statistically significant differences among each other (p > 0.05). Data are seen in table I. According to table II, for open field device, the variables central segment and self-cleaning did not show statistically significant differences among groups (p > 0.05). For the variable peripheral segment, there were a greater amount of segments f lown in ALG than in LG. The other groups behaved similar among each other (p > 0.05).

Concerning to the variable standing up from open field, SLG was the most frequent group. There were not significant statistically differences (p > 0.05) between CG and LG. SLG behaved different from ASLG and ALG (p < 0.05).

Table I – Evaluations of the CNS in maze cross device. Means and standard deviations

Group N

Amount of entrances Time of permanence Amount of entrances Time of permanence Open 1.50 ± 1.06 ab

Close

CG

8

50.37 ��������� ± 63.03 a �

1.75 ± 1.38 a

224.62 ± ��������� 67.35 ������� a

ASLG

8

2.75 ± 1.48 b

49.25 ��������� ± 30.12 � a

5.25 ± 3.10 b

218.25 ± ��������� 40.68 ������� a

SLG

8

1.75 ± 1.38 ab

32.50 ± ��������� 21.04 a �

3.00 ± 2.67 a

252.50 ± ��������� 50.00 ������� a

ALG

8

1.37 ± 1.40 ab

36.87 ± ��������� 50.91 a �

1.50 ± 1.06 a

249.37 ��������� ± 57.22 ������� a

LG

8

1.00 ± 0.92 a

27.50 ��������� ± 29.39 a �

1.62 ± 0.74 a

258.00 ± ��������� 43.20 ������� a

* Different letters column-wise mean statistically significant differences among groups (p < 0.05)

Table II – Evaluations of the CNS in open field. Means and standard deviations

Group N

Central segment

Peripheral segment

Self-cleaning

On two paws

62.00 ± 27.00 a,b

1.00 ± 0.75 a

3.12 ± 4.64 a,b

CG

8

3.12 ± 3.52 a

ASLG

8

4.25 ± 2.65 a

65.12 ± 25.78 a,b

2.00 ± 1.19 a

0.75 ± 0.88 a

SLG

8

4.37 ± 3.99 a

55.50 ± 23.52 a,b

1.62 ± 1.50 a

5.50 ± 4.89 b

ALG

8

3.12 ± 2.79 a

73.75 ± 11.86 b

1.12 ± 0.99 a

1.37 ± 2.13 a

LG

8

5.50 ± 3.11 a

47.50 ± 16.05 a

1.25 ± 1.16 a

2.00 ± 2.82 a,b

* Different letters column-wise mean statistically significant differences among groups (p < 0.05)

Discussion Under these experimental conditions, the study demonstrated that the chronic use of alcohol associated with stress and ligature-induced periodontitis was capable of providing small alterations in the behavior of the animals. The alcoholism for longer periods causes several biochemical and physiological

255 – RSBO. 2013 Jul-Sep;10(3):252-6 Semenoff� et al. – Ligature-induced ������������������������������� periodontitis associated �������������� to alcohol �������������� using and �������������� stress on ��������� animal’s behavior: ���������������� study in ������� rats

abnormalities in the human body [9] and it is also a contributing factor in the induction of the diseases such as cancer [13] and periodontitis [15].

Additionally to alcoholism, emotional diseases have been increasingly more frequent in modern life and they have intensified the decrease of quality of life [3, 25]. This health neglect due to stress, mainly in large cities, has intensified the emotional and physical problems, injuring the immune system [3]. The study results evidenced that the stress associated with periodontitis induction alone also caused, sometimes, a slight change in the behavior of the animals. The association of these two factors occurred according to the results of this study, which corroborates with other findings previously reported [17, 18, 23].

It could be hypothesized that there would be results with greater differences among the variables.

The chronic use of alcohol and stress could have caused the adaptation of animals in this evaluation parameter [15]. The distinguished Hans Selye advocated this situation type as adaptation phase [6].

Most times, the mammalian are resistant; however, after injury by external agents for longer times, any organ or system always decompensate. These information are proved true through the evaluation of the periodontal structures in histological findings. In these groups, there had been a greater destruction of loose conjunctive tissue, bone conjunctive tissue and epithelial tissue [8]; in addition, the hematopoietic system has also exhibited variations in the same stress model [10]. It is important to emphasize that methodologies similar to the stress induction and abusive use of alcohol were capable of modifying the physiology of the animal [14, 15].

The choice for the percentage of alcohol level of this study was based on both the values found in daily market alcoholic beverages and information reported in the literature [15, 19]. The methodology of the evaluation of the behavior of the central nervous system was based on the literature [4, 7, 14], and its relationship with the dental problems starts to be explored [14]. Notwithstanding, the etiopathogeny of periodontitis has still aspects of difficult understanding and it becomes more comprehensive when the behavior and alcoholism are considered. Despite of the limitations of this study, such as the auxiliary examinations and sample size, the results were interesting. Actually, the longer time of stress and alcohol use seemed to cause the adaptation of the animals in the behavioral analyses used in this study. Further studies are necessary to achieve more consistent results regarding to the three problems of public health involved in this study.

Conclusion Based on the methodology employed in this study, it was possible to verify that the use of alcohol associated with chronic stress and periodontitis induction demonstrated few alterations in the behavior of the animals.

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8. D h a b h a r FS , M c E we n BS , S p e n c e r R L. Adaptation to prolonged or repeated stresscomparison between rat strains showing intrinsic differences in reactivity to acute stress.

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9. ������������������������������������������ Faustino SE, Stipp AC. Effects of chronic alcoholism and alcoholic detoxication on rat submandibular glands: morphometric study. J Appl Oral Sci. 2003 Mar;11(1):21-6.

10. Frussa-Filho R, Ribeiro RA. One-trial �������������������� tolerance to the effects of chlordiazepoxide in the elevated plus-maze is not due to acquisition of a phobic avoidance of open arms during initial exposure.

Life Sci. 2002 Jun 21;71(5):519-25.

11. Glaser R. Stress-associated immune dysregulation and its importance for human health: a personal history of psychoneuroimmunology.

Brain Behav Immun. 2005 Jan;19(1):3-11.

12. Needleman I, McGrath C, Floyd P, Biddle A. Impact of oral health on the life quality of periodontal patients. J Clin Periodontol. 2004 Jun;31(6):454-7.

13. Popp W, Schell C, Kraus R, Vahrenholz C, Wolf R, Radtke J et al. DNA strand breakage and DNA adducts in lymphocytes of oral cancer patients.

Carcinogenesis. 1993 Nov;14(11):2251-6.

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15. Porto AN, Semenoff Segundo A, Vedove Semenoff TA, Pedro FM, Borges AH, Cortelli JR et al. Effects ������������������������������������������������� of forced alcohol intake associated with chronic stress on the severity of periodontitis: an animal model study. Int J Dent. 2012:1-6.

16. Reiche EMV, Nunes SOV, Morimoto HK. Stress, depression, the immune system, and cancer. Lancet Oncol. 2004 Oct;5(10):617-25.

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Effects of two chronic stress models on ligatureinduced periodontitis in Wistas rats. Arch Oral Biol. 2012 May;57(5):477-82.

19. Semenoff Segundo A, Semenoff TADV, Biasoli ER. ���������������������������������������� Efeito da ingestão crônica de álcool na progressão de periodontite induzida em ratos da linhagem Fischer-344. RGO. 2009;57(1):87-91.

20. Semenoff TADV, Semenoff Segundo A, Bosco AF, Nagata MJH, Garcia VG, Biasoli ER. Histometric ����������������������������������������� analysis of ligature-induced periodontitis in rats: a comparison of histological section planes. J �������������������������� Appl Oral Sci. 2008 JulAug;16(4):251-6.

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ISSN: Electronic version: 1984-5685 RSBO. 2013 Jul-Sep;10(3):257-65

Original Research Article

Evaluation of the effectiveness of manual and rotary techniques in the desobturation and reinstrumentation of root canal Érica Pozo Mautone1 Elias Pandonor Motcy de Oliveira1 Simone Viegas da Silva Bonatto1 Tiago André Fontoura de Melo1 Corresponding author: Érica Pozo Mautone Rua Baronesa do Gravataí, n. 594 – Menino Deus CEP 90160-070 – Porto Alegre – RS – Brasil E-mail: epozo@terra.com.br 1

Department of Dentistry, Lutheran University of Brazil – Canoas – RS – Brazil.

Received for publication: February 21, 2013. Accepted for publication: April 22, 2013.

Keywords: Endodontics; retreatment; instrumentation.

Abstract Introduction and Objective: This study aimed to evaluate the ability of desobturation and reinstrumentation of root canal with manual and rotary techniques. Material and methods: Sixty single-rooted incisors were selected, prepared with ProTaper® rotary system and obturated with gutta-percha and AH Plus®, using the lateral condensation technique. The teeth were restored with Cimpat® and were kept for 90 days at 37°C and 100% humidity. After this period, the teeth were divided into three groups according to the technique of desobturation and reinstrumentation. In group A, D1, D2 and D3 instruments of ProTaper® system for desobturation were used associated with F4 instrument of the same system for reinstrumentation. In group B, K type manuals instruments were employed in the desobturation and reinstrumentation. The teeth of group C (control) were not treated. After the desobturation and reinstrumentation steps of groups A and B, the teeth were radiographed at mesiodistal and labial-lingual incidences. The images were evaluated by three examiners previously trained and calibrated.

Results and Conclusion: The data were statistically analyzed and showed no significant differences in the amount of the remaining filling material tested by both techniques, except from the medium

258 – RSBO. 2013 Jul-Sep;10(3):257-65 Mautone� et al. – �������������� Evaluation of ��������������������� the effectiveness of ����������� manual and ������� rotary ������������������������������������ techniques in the desobturation and ������������������ reinstrumentation of root canal

third, at mesiodistal direction, in which the rotary technique was more effective. There was no difference in the cleaning of the canal walls after the desobturation and reinstrumentation. The apical third showed the largest amount of remaining material, regardless of the technique used.

Introduction

Material and methods

The success rate of the endodontic retreatment still shows a great variability [26, 28]. According to Paik et al. [21], the success rate of the retreatment has been related in the literature between 40 and 100%.

This variation in treatment success, on the other hand, is related to several factors, such as: periapical condition [15], quality of coronal restorat ion [20] a nd abi lit y of remov i ng a ll endodontic filling material [7].

Currently, a variety of techniques and devices is employed and studied for the desobturation of root canals: use of hand endodontic instruments, heat instruments, sonic and ultrasonic devices, laser and rotary instruments [2, 4, 5, 8, 10, 16].

Notwithstanding, to date, none of these resources is totally efficient in removing the filling material [1, 9, 13, 19].

Schwerz et al. �������������������������������� [25] compared the effectiveness of NiTi rotary system, Gates-Glidden burs and the use of hand instruments in the desobturation of root canals. The authors concluded that the ProTaper ® retreatment system was faster and more effective in the gutta-percha removal than hand technique with Flexofile instruments and Gates-Glidden burs.

On the other hand, Queiróz et al. [22] analyzed the ProTaper® rotary system and K type hand instruments in the endodontic desobturation and they could verify through diaphanization that there were no differences between the two techniques for the removal of the filling material.

In 2013, Klalilak et al. [17] evaluated the efficacy of the ProTaper® rotary system and HFile® hand instrument in the desobturation of root canals. They observed that the use of the rotary system was more efficient and faster in removing the filling material.

Thus, the aim of this study was to evaluate through radiographs the ability of desobturation and reinstrumentation of the root canal by using hand and rotary techniques.

This study was approved by t he Et hica l Committee in Research in Human Beigns and Aninals of the Lutheran University of Brazil (under protocol number #2007 427H).

Sixty single-rooted mandibular incisors were used. After the surgical access, the working lenght was determined and standardized at 1 mm short of the foramen opening.

Next, the roots were individually immersed into blocks of chemically-activated acrylic resin (Clássico, Brazil), aiming to standardize the radiographic shots, so that the teeth were kept at the same position.

Root canal preparation was executed through the rotary technique at crown-down technique with the ProTaper® system (Dentsply/Maillefer, Ballaigues, Switzerland). The instruments were motor driven (Endo Pro Torque - VK Driller Equipamentos Elétricos, Brasil) at a speed of 250 rpm and torque of 2 N/cm 2 . The memory instrument was standardized at size 3 Finishing File (F3).

At each instrument change, the root canals were irrigated with 2 ml of 1% sodium hypochlorite (Farmácia Escola da Ulbra – Campus Canoas/ RS, Brazil). In the ending of the preparation the canals were irrigated with 17% EDTA (Iodontosul – Industrial Odontológica do Sul Ltda., Porto Alegre, Brazil) for 3 minutes, followed by 1% sodium hypochlorite.

Next, the root canals were dried with size F3 paper points (Dentsply/Maillefer, Ballaigues, Switzerland), and the gutta-percha master cone was determined by size F3 instrument (Dentsply/ Maillefer, Ballaigues, Switzerland).

During the obturation process, AH Plus ® endodontic cement (Dentsply/Maillefer, Ballaigues, Switzerland) was used together with size B7 accessory gutta-percha points (Tanari®, Manaus, Amazonas, Brazil), following the manufacturer’s instructions. The accessory points were also involved into endodontic cement and inserted into

259 – RSBO. 2013 Jul-Sep;10(3):257-65 Mautone� et al. – Evaluation �������������� of the ��������������������� effectiveness of manual ����������� and rotary ������� techniques ������������������������������������ in the desobturation and reinstrumentation ������������������ of root canal

the open spaces. This was repeated until the size B spacer (Dentsply/Maillefer, Ballaigues, Switzerland) could not be inserted anymore. The obturation technique used was lateral condensation and vertical adaptation with the aid of size 3 Paiva condenser (SSWhite, Rio de Janeiro, Brazil).

After the ending of the endodontic treatment, the teeth were sealed with temporary restorative material (Cimpat® -Septodont Brasil Ltda., São Paulo, Brazil).

Following, the teeth were kept into flasks with distilled water (Iodontosul – Industrial Odontológica do Sul Ltda., Porto Alegre, Brazil) taken into an incubator (Fabbe-Primar Equipamentos e Serviços Ltda., São Paulo, Brazil) at 37°C, with 100% humidity, for 90 days.

Elapsed this time, the teeth were randomly divided into three experimental groups (table I), to be submitted to the procedures of desobturation and reinstrumentation.

Table I – Experimental groups

Group

Number of teeth

Technique of desobturation and reinstrumentation

A

20

Desobturation = ProTaper® system (sizes D1, D2, D3) Reinstrumentation = ProTaper® system (size F4)

B

20

Desobturation = K type hand instrumentation Reinstrumentation = K type hand instrumentation

C

20

None

In group A, the desobturation of the root canal was executed with ProTaper® reinstrumentation system coupled with a contra-angle handpiece (Dabi Atlante, Ribeirão Preto, São Paulo, Brazil) and motor driven (Endo Pro Torque®), at a constant speed of 300 rpm and torque of 2 N/cm² [6].

The enlargement movements with constant rotation were performed in the following sequence: size D1, D2 and D3 instruments onto the cervical, medium and apical thirds, respectively. During the reinstrumentation, the size File 4 (F4) instrument of ProTaper® Finishing system was used at the working length.

In group B, root canal desobturation was executed with K type hand instruments. The procedure was completed when the size 30 K file reached the working length and no material remnants were seen. Next, the canals were reinstrumented with sizes 35 and 40 endodontic instruments through sharpening movements, at the working length.

Both in groups A and B, at every instrument change, root canal was irrigated with 2 ml of 1% sodium hypochlorite. Eucalyptol (Iodontosul – Industrial Odontológica do Sul Ltda., Porto Alegre, Brazil) was used as solvent agent during the desobturation procedures. During all procedures, both hand and rotary instruments were used at most five times and then discarded [24].

All study steps were executed by a single operator who was Specialist in Endodontics.

To assess the condition of the root canal walls regarding to the presence or absence of filling material remnants, a digital radiographic shot was executed after the desobturation and reinstrumentation procedures at two incidences: mesiodista l a nd labia l-lingua l, enabling t he assessment of the labial and proximal views of each sample.

The specimens were placed into a radiographic platform and the Charge-Coupled Device (CCD) sensor (Cygnus Ray - Progeny Dental, Buffalo Grove, Illinois USA) was positioned parallely to the specimens (labial and mesial surface), at vertical position. The cylinder of TimeX device (70 kV, 7 mA, Gnatus, Riberão Preto, SP, Brazil) was positioned in order to enable that the central ray perpendicularly reached the CCD sensor, with focal distance of 28 cm and 1.5 second of exposure.

The radiographic images obtained were divided into three thirds (cervical, medium and apical) and assessed by three examiners, specialists in Endodontics, which were previously trained and calibrated.

The examiners scored the images regarding to the amount of remaining material, as follows (figure 1): – Score 1 = lack of filling material; – Score 2 = presence of up to 50% of filling material; – Score 3 = presence of more than 50% of filling material.

260 – RSBO. 2013 Jul-Sep;10(3):257-65 Mautone� et al. – Evaluation �������������� of the ��������������������� effectiveness of manual ����������� and rotary ������� techniques ������������������������������������ in the desobturation and reinstrumentation ������������������ of root canal

Figure 1 – Radiographic images, at the two radiographic incidences, regarding to the score of each root third C = cervical third; M = medium third; A = apical third

The results were submitted to statistical analysis through Mann-Whitney and Friedman nonparametric tests followed by the test of multiple comparisons with level of significance of 5%.

Results By applying Kendall coefficient of concordance, it was observed a good inter-examiner agreement whose index was of 0.860 for the apical third, 0.825 for the medium third, and 0.883 for cervical third.

Because in group C (control) the teeth were not desobturated and reprepared, the radiographic examination showed 100% of filling material presence. Due to that reason, there was no need to execute the comparative statistical analysis with the two other groups.

Aiming to compare the desobturation of the canal between the experimental groups, Mann-Whitney non parametric test was used and showed that there were no statistical significant differences between groups, except for the medium third where the rotary system exhibited the lowest scores (table II).

Table II – Desobturation of root canals between the experimental groups and at the two radiographic incidences

Root thirds Incidence

Score

Cervical Rotary

M-D

Hand

Apical

Rotary

Hand

Rotary

Hand

1

7

4

2

0

0

0

2

13

15

15

6

3

1

3

0

1

3

14

17

19

Total

20

20

20

20

20

20

0.327

p

V-L

Medium

0.001

0.602

1

9

4

2

1

0

0

2

10

13

9

4

2

1

3

1

3

9

15

18

19

Total

20

20

20

20

20

20

p

0.114

0.108

0.799

p = minimum level of significance of Mann-Whitney non-parametric test

By comparing the rotary group after the desobturation and reinstrumentation procedure, no significant differences were found after Mann-Whitney non-parametric test (table III).

261 – RSBO. 2013 Jul-Sep;10(3):257-65 Mautone� et al. – Evaluation �������������� of the ��������������������� effectiveness of manual ����������� and rotary ������� techniques ������������������������������������ in the desobturation and reinstrumentation ������������������ of root canal

Table III – Desobturation and reinstrumentation with the rotary system at the root thirds and at the two radiographic incidences

Root thirds Cervical

Incidence Score

M-D

Apical

Desobturation

Reinstrumentation

Desobturation

Reinstrumentation

Desobturation

Reinstrumentation

1

7

8

2

3

0

0

2

13

12

15

14

3

3

3

0

0

3

3

17

17

Total

20

20

20

20

20

20

0.799

p

V-L

Medium

0.820

1.000

1

9

9

2

4

0

0

2

10

9

9

9

2

3

3

1

2

9

7

18

17

Total

20

20

20

20

20

0.883

p

0.445

20 0.799

p = minimum level of significance of Mann-Whitney non-parametric test

In the comparison of hand group between desobturation and reinstrumentation there were no statistical significant differences after Mann-Whitney non-parametric test (table IV).

Table IV – Desobturation and reinstrumentation with the rotary system at the root thirds and at the two radiographic incidences

Root thirds Cervical

Incidence Score

M-D

Desobturation

1

4

2

Apical

Desobturation

Reinstrumentation

Desobturation

Reinstrumentation

7

0

0

0

0

15

12

6

11

1

1

3

1

1

14

9

19

19

Total

20

20

20

20

20

20

0.445

p

V-L

Medium

Reinstrumentation

0.183

1.000

1

4

7

1

0

0

0

2

13

9

4

6

1

1

3

3

4

15

14

19

19

Total

20

20

20

20

20

20

p

0.640

0.862

1.000

p = minimum level of significance of Mann-Whitney non-parametric test

When the comparison among the three root canal thirds was performed through Friedman nonparametric test, followed by the Test of multiple comparisons with level of significance of 5%, it was verified that at the mesiodistal direction in the rotary groups (desobturation and reinstrumentation) at the apical third, the scores attributed were significantly higher than those of the other thirds. In the hand groups (desobturation and reinstrumentation) the scores attributed to the apical thirds were significantly higher than those attributed to the cervical third, but without significant differences from those of the medium third (table V).

262 – RSBO. 2013 Jul-Sep;10(3):257-65 Mautone� et al. – Evaluation �������������� of the ��������������������� effectiveness of manual ����������� and rotary ������� techniques ������������������������������������ in the desobturation and reinstrumentation ������������������ of root canal

Table V – Comparison among groups at the three root thirds, at the mesiodistal radiographic incidence

Group

Rotary (desobturation)

Hand (desobturation)

Rotary (reinstrumentation)

Hand (reinstrumentation)

Score

Root thirds Cervical

Medium

Apical

1

7

2

0

2

13

15

3

3

0

3

17

Total

20

medium Rank

1.35

1.825

2.825A

1

4

0

0

2

15

6

1

3

1

14

19

Total

20

medium Rank

1.15

2.28

1

8

3

0

2

12

14

3

3

0

3

17

Total

20

medium Rank

1.38

1.80

2.83A

1

7

0

0

2

12

11

1

3

1

9

19

Total

20

medium Rank

1.23

20 B

20 B

20 B

20 A

20 B

20 B

20 B

2.58A

2.08

20 A

2.70A

For each group, medium ranks followed by different letters differed significantly through Friedman non parametric test, followed by the test of multiple comparisons with the level of significance of 5%

In the comparison between the experimental groups at the three root thirds, at the labial-lingual direction by applying Friedman non parametric test, followed by the test of multiple comparisons with the level of significance of 5%, it was observed that in the rotary group (desobturation) and hand group (desobturation and reinstrumentation) the scores attributed to the apical third were significantly higher than those given to the cervical third, but without statistically significant differences from those of the medium third. For the rotary group (reinstrumentation), the scores attributed to the apical third were significantly higher than those of apical and medium thirds (table VI).

Table VI – Comparison among groups at the three root thirds, at the labial-lingual radiographic incidence l

Group

Rotary (desobturation)

Score

Root thirds Cervical

Medium

Apical

1

9

2

0

2

10

9

2

3

1

9

18

Total

20

medium Rank

1,28

20 B

20

2,05

A

2,68A

263 – RSBO. 2013 Jul-Sep;10(3):257-65 Mautone� et al. – Evaluation �������������� of the ��������������������� effectiveness of manual ����������� and rotary ������� techniques ������������������������������������ in the desobturation and reinstrumentation ������������������ of root canal

Table VI (continued)

Group

Hand (desobturation)

Rotary (reinstrumentation)

Hand (reinstrumentation)

Score

Root thirds Cervical

Medium

Apical

1

4

1

0

2

13

4

1

3

3

15

19

Total

20

20

20

medium Rank

1,28B

2,20A

2,53A

1

9

4

0

2

9

9

3

3

2

7

17

Total

20

medium Rank

1,38

1,95

2,68A

1

7

0

0

2

9

6

1

3

4

14

19

20 B

20 B

Total

20

20

20

medium Rank

1,28B

2,23A

2,50A

For each group, medium ranks followed by different letters differed significantly through Friedman non parametric test, followed by the test of multiple comparisons with the level of significance of 5%

Discussion The removal of a preexisting filling material within root canals is of fundamental importance to obtain success in endodontic retreatment [22].

For this reason, there is a constant searching for new techniques that make easy the removal of this filling material. The rotary instruments are a reality today in Endodontics and its use during endodontic retreatment has been searched by diverse researches [5, 19, 29].

The ProTaper® system has been already studied by several authors [12-14, 23], who evidenced its good performance in the desobturation of the root canals.

Notwithstanding, likely other rotary systems, this system was not capable of removing completely the filling material. Other studies [11, 22] also observed this same research.

Concerning to the efficacy of the techniques tested, the results did not show statistic differences in the amount of remaining material after the desobturation and reinstrumentation. These findings are in agreement with other studies previously conducted by Schirmeister et al. [24], Gergi and Sabbagh [12] and Barletta et al. [3].

A better cleaning of the root canal walls was obtained with the rotary technique than with the

hand technique, only at the medium third, at the mesiodistal direction. This probably occurred because of the design of the ProTaper® instruments, which exhibited a greater taper than standardized hand files, enabling a greater contact of the instrument with the root canal walls during its action.

Marques da Silva et al. [18] ������������������ did not find statistically significant difference regarding the amount of remaining filling material after retreatment when ProTaper® retreatment system, D-Race® system and MTwo® retreatment instruments were compared, even when additional instruments had been employed for reinstrumentation.

In relation to the analysis of the removal of the filling material among the root thirds, it could be observed that the apical third was the region that showed the greatest amount of remaining filling material, regardless of the operative technique used. Other studies [22, 25, 27] also verified this same situation. Only in the study conducted by Garcia Júnior et al. [11] the apical third exhibited the smallest amount of remaining filling material, followed by medium and cervical third.

Based on the results of this study, further studies are necessary because an efficient and safe technique has not been found for the total removal of the filling material.

264 – RSBO. 2013 Jul-Sep;10(3):257-65 Mautone� et al. – Evaluation �������������� of the ��������������������� effectiveness of manual ����������� and rotary ������� techniques ������������������������������������ in the desobturation and reinstrumentation ������������������ of root canal

Conclusion According to the results obtained, it can be concluded that: • Hand and rotary techniques were not capable of removing completely the filling material inside root ca na ls. The rotary technique was most efficient only at the medium third, at mesiodistal direction, without statistically significant difference between the two techniques at the other thirds and directions; • Concerning to the cleaning of the root canal walls after desobturation and reinstrumentation, there were not statistically significant differences, regardless of the technique used; • The apical third showed the greatest amount of filling material after the desobturation and reinstrumentation of the root canals in both techniques tested.

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10. Ferreira JJ, Rhodes JS, Ford TR. The efficacy of gutta-percha removal using ProFiles. Int ���������� Endod J. 2001;34(4):267-74.

11. Garcia Júnior JS, Silva Neto UX, Carneiro E, Westphalen VPD, Fariniuk LF, Fidel RAS et al. Avaliação radiográfica da eficiência de diferentes instrumentos rotatórios no retratamento endodôntico. RSBO. ��������������������� 2008;5(2):41-9.

12. Gergi R, Sabbagh C. Effectiveness of two nickel-titanium rotary instruments and a hand file for removing gutta-percha in severely curved root canals during retreatment: an ex vivo study. Int Endod J. 2007;40(7):532-7.

13. Huang X, Ling J, Wei X, Gu L. Quantitative evaluation of debris extruded apically by using ProTaper Universal Tulsa rotary system in endodontic retreatment. J Endod. 2007;33(9):1102-5.

14. Hülsmann M, Bluhm V. Efficacy, cleaning ability and safety of different rotary NiTi instruments in root canal retreatment. Int ������������������������������� Endod J. 2004;37(7):468-76.

15. Imura N, Pinheiro ET, Gomes BP, Zaia AA, Ferraz CC, Souza Filho FJ. The ��������������� outcome of endodontic treatment: a retrospective study of 2000 cases performed by a specialist. J ��������� Endod.

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16. Imura N, Kato AS, Hata GI, Uemura M, Toda T, Weine F. A comparison of the relative efficacies of four hand and rotary instrumentation techniques during endodontic retreatment. Int Endod J. 2000;33(4):361-6.

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18. Marques da Silva B, Baratto-Filho F, Leonardi DP, Henrique Borges A, Volpato L, Barletta FB. Effectiveness of ProTaper, D-RaCe, and Mtwo retreatment files with and without supplementary instruments in the removal of root canal filling material. Int Endod J. 2012;45(10):927-32.

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ISSN: Electronic version: 1984-5685 RSBO. 2013 Jul-Sep;10(3):266-71

Original Research Article

Burnout syndrome: evaluation in dentists in the city of Fortaleza, Brazil Sandro Dias Rocha Mendes Carneiro1 Camila Castro Tourinho1 Tathiane Araújo Pedrosa do Vale1 Yvonne de Souza Gurjão Campêlo1 Fábio de Almeida Gomes1 Danilo Lopes Ferreira Lima1 Corresponding author: Sandro Dias Rocha Mendes Carneiro Avenida Antonio Sales, n. 3.525, apto 1.801 – Dionísio Torres CEP 60135-102 – Fortaleza – CE – Brasil E-mail: sandrodiasr@hotmail.com 1

School of Dentistry, University of Fortaleza – Fortaleza – Ceará – Brazil.

Received for publication: February 12, 2013. Accepted for publication: April 24, 2013.

Keywords: Burnout syndrome; dentists; occupational disease.

Abstract Objective: The objective of this study was to assess the occurrence of burnout syndrome in dentists in the city of Fortaleza. Material and methods: By means of an analytical-descriptive research of quantitative character through the application of a MBI (Maslach Burnout Inventory) and a socio-cultural questionnaire. Results: The sample of 100 respondents was equally divided into female and male (50%), with a mean age of 38.09 years, 60% married, 34% single and 6% divorced. Most of the participants had between one and 20 years of tenure (62%), with a predominance of weekly working hours from 21 to 40 hours (44%). Conclusion: Burnout syndrome was diagnosed in 32% of respondents, without statistical significant differences in the relationship among gender and working hours, marital status and years of tenure (Mann Whiteney p < 0.005).

Introduction The occupational stress is an issue gaining attention worldwide. Because of the technological advancements and innovations occurring in countless managements of institutions, the requirements and

demands for a trained professional that have an excellent working development are indispensable every day. With all responsibility to be executed and the constant requirements of the modern life, the stress in the working environment is every time

267 – RSBO. 2013 Jul-Sep;10(3):266-71 Carneiro� et al. – Burnout �������������������������������� syndrome: evaluation in dentists ������������������������ in the city of Fortaleza, ����������� Brazil ������

more common, which can result in diseases such as the Burnout syndrome.

I n 19 74 , t h e p s y c h o l o g i s t H e r b e r t J. Freudenberger observed that the employees of a clinic for drug addicts in the United States were unstimulated to help the patients, because these did not make any effort to follow the treatment.

Therefore, it could be observed that the employees showed some symptoms that had been associated with the Burnout syndrome [7].

Freudenberger, in its first definition, affirms that: “The Burnout is the result of exhaustion, disappointment and loss of interest in work activity, which appears in the professions that work in direct contact with people providing services such as the consequence of this daily contact in its work” [23]. Although Freudenberger was not the first author to report on the Burnout syndrome to refer to the physical and mental exhaustion and to the behavioral disorders, his studies are the keystones on this issue and they accounted for other studies that increase the concept of Burnout [2].

Sometime later, Maslash and Jackson [15] defined Burnout as being a syndrome of emotional distress, depersonalization and low personal accomplishment, in which the emotional distress is considered the initial symptom and the most obvious sign of Burnout syndrome is characterized by mental and physical exhaustion in which the person is without energy and willingness to work. The depersonalization occurs just after the tiredness, characterized by a certain distancing from people to whom they work for and from coworkers, acquiring many times snarling, cynical, inhuman behaviors without affection. The low personal satisfaction is characterized by the loss of satisfaction in working and consequently in lack of efficiency so that the work becomes a burden to the person, [8, 11, 13, 16, 17]. This process occurs sequentially, that is, first the emotional exhaustions appears and this will conduct to the development of the depersonalization; on the other hand, low personal satisfaction is developed separately [14].

Since then, several authors such as Codo and Vasques-Meneses [5], Murofuse et al. [18], among others, exposed their definitions on Burnout.

According to Accioly [1], although the Burnout syndrome is the result of a prolonged stress,

it cannot be considered as stress because this later involves excess in which the person fells under pressure, demanding both physical and psychological effort. Notwithstanding, the person cares about the work and when he/she solves the problem he/she becomes to feel good. On the other hand, the Burnout comprises absence, that is, lack of motivation, the hope that something could change his/her situation. The author cited among the causative factors of Burnout: professionals who feel criticized, misunderstood, underpaid, who dedicated their time to take care for people; who defined unreal goals for themselves, where there is excessive working demand; when they work in something that frequently violates their personal values; who work repetitively, among others.

Therefore, if the working days were considered as bad; the worry with the work considered as waste of energy; and the tasks considered as boring or unpleasant, this can be a sign of the beginning of Burnout syndrome.

The dentists are part of a profession which is characterized by showing great working hours and has direct and daily contact with patients, who are many times tense and anxious regarding to the treatment they would be submitted, because there is an idea that the dental treatment causes pain. Thus, the Dentistry is a profession that would be prone to develop the aforementioned syndrome. The aim of this study was to determine the prevalence of Burnout syndrome in dentist in the city of Fortaleza and its relationship with gender, years of tenure, marital status, and the weekly working hours.

Material and methods This was a cross-sectional study of quantitative character, comprising two questionnaires aiming to identify and classify the level of Burnout syndrome in dentists. The sample was composed of 100 professionals working in the city of Fortaleza (Ceará, Brazil).

The following questionnaires were applied: • Social-cultural: with questions related to work and the health of the participant; age; gender; marital status; years of tenure; and working hours per week.

• Maslach Burnout Inventory (MBI): used in its adapted version and validated in Portuguese

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by Tamayo and Trócolli [24]. It comprises 22 quest ions, w it h 5 response opt ions (Li kert sca le from 1 to 5), which include t he t hree fundamental aspects of the Burnout syndrome.

The emotional exhaustion was evaluated by nine items (questions 1, 2, 3, 6, 8, 13, 14, 16 and 20); the depersonalization by five (questions 5, 10, 11, 15 and 22) and personal fulfillment (questions 4, 7, 9, 12, 17, 18, 19 and 21).

Datum tabulation, processing and analysis were performed by usi ng Epi In fo soft wa re version 3.4.3.

Results

Criteria for the interpretation of the results

Table I – Social-cultural data from 100 dentists interviewed

MBI comprises three dimensions: the emotional ex haust ion, t he depersona l i zat ion, a nd t he decreased personal fulfillment (disappointment).

The responses are the frequency with which the participant either perceives or experiences the feeling or attitude: never (1), occasionally, less than once per week (2), almost frequently, once or twice per week (3), frequently, three or four times per week (4) and daily (5).

Considering to the emotional exhaustion, a score greater or equal to 27 indicates high level; from 19 to 26, moderate level; and smaller than 19, low level. For depersonalization, scores greater or equal to 10 indicates high level; from 6 to 9, moderate level; and smaller than 6, low level. The score related to the personal fulfillment is the opposite, with scores from 0 to 33 indicating high level; from 34 to 39, moderate level and greater or equal to 40, low level.

The patients showing high scores for either emotional exhaustion or depersonalization; or low scores for personal fulfillment were considered with Burnout syndrome.

All ethical aspects – beneficence, non-maleficence, justice and equity – were strictly observed. The participant had to sign a free and clarified consent form where they were informed regarding the purpose of the research. The participants had the right to abandon the research at any time.

The participants in the research were instructed regarding to the prevention of occupational diseases with the knowledge of their actual state in relation to the professional stress.

A descriptive analysis of the distributions, verification of data consistency and categorization of continuous or discrete variables were performed.

One hundred questionnaires were sent back, with a response rate of 100% because all dentists agreed in responding the questions. The sample comprised an equal number of female (n = 50; 50%) and male (n = 50; 50%). Concerning to the marital status, 60 (60%) participants reported to be married; 34 single (34%); and 6 (6%) divorced. In relation to the years of tenure and working hours, most of the respondents had between 1 and 10 years of tenure and worked from 21 to 40 hours per week, corresponding to 40% and 44% of the total, respectively (table I).

Gender Female Male Marital status Single Married Divorced Age 19 to 39 years 40 to 59 years 60 to 80 years Working hours per week Up to 20 hours 21 to 40 hours More than 40 hours Years of tenure 1 to 10 years 11 to 20 years More than 20 years

50 (50%) 50 (50%) 34 60 6 mean 60 37 3

(34%) (60%) (6%) = 38.09 (60%) (37%) (3%)

16 (16%) 44 (44%) 40 (40%) 40 (40%) 32 (32%) 28 (28%)

In the sample studied, the Burnout syndrome was diagnosed in 32 participants (32%) out of 100 respondents. Sixty-eight (68%) did not show the syndrome. By individually analyzing each dimension of the syndrome, the following means were obtained: emotional exhaustion – 19.5 points; depersonalization – 7.4 points, both representing the moderate level; and personal fulfillment - 32 points, representing the high level. Concerning to the gender, in each dimension, the following means were obtained: female – emotional exhaustion - 20 points; depersonalization – 7.5 points; and personal fulfillment - 31.7 points; male – emotional exhaustion - 18.9 points; depersonalization - 7.4 points; and personal fulfillment - 32.4 points (table II).

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Table II – Results of the Maslach Burnout Inventory (MBI) from the 100 dentists interviewed

Burnout Syndrome Diagnosed Undiagnosed Grunfeld et al. [10] Ramirez et al. [20] Female Emotional exhaustion Depersonalization Personal fulfillment Male Emotional exhaustion Depersonalization Personal fulfillment Total Emotional exhaustion Depersonalization Personal fulfillment

32 (32%) 68 (68%) 32 0 Mean 20 7.5 31.7 Mean 18.9 7.4 32.4 Mean 19.5 7.4 32

SD ± 7.6 ± 2.7 ± 5.2 SD ± 5.7 ± 2.3 ± 5.5 SD ± 6.7 ± 2.5 ± 5.3

By analyzing the data regarding to the 32 respondents showing the Burnout syndrome, it was observed that 17 (53.1%) were female and 15 (46.9%) were male. Concerning to the years of tenure, 11 (34.4 %) had between 1 and 10 years; 11 (34.4%) had between 11 and 20 years and 10 (31.2%) had more than 20 years. The analysis of the week hours showed that only 3 (9.4%) worked up to 20 hours, 12 (37.5%) from 21 to 40 hours and 17 (53.1%) more than 40 hours. Concerning to the marital status, 18 (56.3%) were married, 11 (34.4%) were single and 3 (9.4%) were divorced (table III).

Table III – Result of MBI from the 32 dentists exhibiting the Burnout syndrome

Gender Female Male Marital status Single Married Divorced Working hours per week Up to 20 hours 21 to 40 hours More than 40 hours Years of tenure 1 to 10 years 11 to 20 years More than 20 years

17 (53.1%) 15 (46.9%) 11 (34.4%) 18 (56.3%) 3 (9.4%) 3 (9.4%) 12 (37.5%) 17 (53.1%) 11 (34.4%) 11 (34.4%) 10 (31.2%)

The analysis of the influence of the variables years of tenure, hours of work, marital status between male and female with Burnout syndrome through Mann Whitney test with level of significance of 5% (p < 0.05) did not show any statistical significant difference.

Discussion The research on Burnout has been increasingly growing and the main investigation tool worldwide is the Maslach Burnout Inventory (MBI).

Because the literature lacks consensus on the interpretation of MBI, the studies show different criteria to classify and diagnose the Burnout.

To assess the dimensions grouped, the criteria exhibited by Ramirez et al. [20] and Grunfeld et al. [10] have been the most used. Ramirez et al. define Burnout when there are high scores for emotional exhaustion and depersonalization and low scores for personal fulfillment. Grunfeld et al., on the other hand, considered the Burnout diagnosed when the individual scored high level for emotional exhaustion or depersonalization or low level for personal fulfillment.

I n t h i s pre s ent st udy, c on sider i n g t he parameters of Grunfeld et al. [10], 32% of the dentists exhibited the syndrome, which was a significant percentage. According to the criteria

by Ramirez et al. [20], none was diagnosed with the sy ndrome; these authors used a stricter classification, as aforementioned. Low Burnout rates were a lso found i n ot her studies [25] employing the criteria by Ramirez et al.

According to Gil-Monte and Peiró [9], the levels of the dimensions of the syndrome tend to vary in relation to the gender. These authors believe that for the emotional exhaustion and lack of personal fulfillment the women score higher; for depersonalization, the men score higher. In this present study, the women exhibited a higher emotional exhaustion mean (20±7.6 points) than that of men (18.9±5.7 points). For the personal fulfillment, the women showed a smaller mean (31.7±5.2 points) than that of men (32.4±5.5 points), confirming the reports of Gil-Monte and Peiró. In relation to depersonalization, the difference between the values for male and female did not show statistical significant differences. By analyzing the marital status, Bianchini-Matamoros [3] affirmed that single people are more prone to develop the syndrome. In this present study, of the 32 dentists exhibiting Burnout syndrome,

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18 (56.3%) were married, 11 (34.4%) were single and 3 (9.4%) were divorced, a result different from that observed by Bianchini-Mataramoros [3].

This author suggests that married people would be more resistant against the syndrome because they feel familial responsibility, with greater ability to face emotional problems [3].

Concerning the working hours per week, 17 (53.1%) worked more than 40 hours, 12 (37.5%) worked from 21 to 40 hours and only three (9.4%) worked up to 20 hours per week. According to Bloise [4], in a study conducted to analyze the sources causing the Burnout syndrome in a group of teachers, the longest working hours are which cause pressure on the professionals, making them susceptible to develop the syndrome. By associating the Burnout syndrome with the years of tenure, we observed that 11 (34.4%) worked between 1 and 10 years and 11 worked between 11 and 20 years (34.4%), while 10 (31.2%) worked for more than 20 years. Thus, more than half of the 32 individuals with the syndrome worked for less than 20 years.

The professionals with less years of tenure tend to idealize expectations for daily practice that not even can be achieved as expected [12].

The a na lysis of t he dent ist s present i n g Burnout syndrome (n = 32) revealed a significantly high value because a little less than a third of them exhibited at least one of the syndrome dimensions at critical levels. Moreover, some authors such as Faber [6] and Benevides-Pereira [2], believe that the respondents may not be responding truthfully what is happening with them because of the content of the questions (“I believe that I treat some people as if they were impersonal objects”, for example). Consequently, these questions may cause certain impact on the respondent, who feel some difficult in assuming certain attitudes that disagree with which is expected from a good professional. Thus, some respondents in this present research may have answered untruthfully, which could create a bias and mask the Burnout syndrome in some cases.

Notwithstanding, this bias can occur in any type of study taking into consideration the subjectivity and self-criticism.

Other important factor to be observed is that although the Burnout syndrome is considered as a consequence of the chronic occupational stress, that is, the pressure suffered in the working environment, each person exhibits a different reaction against the stress [22]. According to�

Prata et al. ���������������������������������� [19], for a long time, individual differences have been observed regarding to resistance to stress. For these authors, some people has a personality type that increases the effects of the stress in working; others has a personality ty pe that makes them worried as time goes by and they can relax more. The authors also cited that there are two types of stress: eustress (good stress), which is healthy by helping the person to execute good things; and distress (bad stress), which is unhealthy, causing undesirable symptoms and diseases. Based on this aforementioned information, it could be noted that the Burnout syndrome depends on the type and intensity of the stress, constancy, the mode of reaction of the person against the stress, among other factors.

Conclusion This present study verified a significa nt amount of dentists exhibiting Burnout syndrome (32%) among the 100 respondents. There were no statistically significant differences regarding to gender in relation to working hours, marital status and years of tenure. Because the prevalence of the Burnout syndrome has been relatively high and increasingly frequent, mainly in professionals taking care of people with closer contact, such as dentists, there is certainly the need of further studies because despite of the higher interest on this issue, it is still unknown by most of the professionals. Thus, a comprehensive divulgation is necessary to enable the professionals to seek effective treatment, as well as prevention and intervention.

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2. Benevides-Pereira AMT. Burnout: quando o trabalho ameaça o bem-estar do trabalhador. São Paulo: Casa do Psicólogo; 2002.

3. Bianchini-Mataramoros M. El síndrome del Burnout em personal profesional de la salud. Med Leg Costa Rica. 1997;13(2-1):189-92.

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4. Bloise D. Análise das características e fontes geradoras da síndrome de Burnout – o caso dos professores de cursos de Administração de universidades privadas. Rev ���������������� Eletro Novo Enfoque. 2009;8(8) [cited 2011 May 21]. Available from: URL:http://www.castelobranco.br/sistema/ novoenfoque/edicao/artigos/8.

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Petrópoles: Vozes; 1999. p. 237-54.

17. Maslash C, Schaufeli WB, Leiter MP. Job Burnout. Annu Rev Psychol. 2001;52:397-422. �����������������

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18. Murofuse NT, Abranches SS, Napoleão AA. Reflexões sobre estresse e Burnout e a relação com a enfermagem. Rev Lat Am Enfermagem.

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7. Freudenberger H. Staff Burnout. J Soc Issues.

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9. Gil-Monte PR, Peiró JM. Influencia del género sobre el proceso de desarrollo del síndrome de quemarse por el trabajo (Burnout) em profesionales de enfermería. Psicologia �������������� em Estudo. 2002;7(1):3-10.

10. Grunfeld E, Whelan TJ, Zitzelsberger L, Willan AR, Montesanto B, Evans WK. Cancer care workers in Ontario: prevalence of Burnout, job stress and job satisfaction. CMAJ. 2000;163(2):166-9.

11. Leiter PM, Maslach C. The impact of interpersonal environment on burnout and organizational commitment. J ��������������� Organ Behav.

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12. Martínez JCA. Aspectos epidemiológicos del síndrome de Burnout en personal sanitario. Rev ���� Esp Salud Pública. 1997;71(3):293-303.

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19. Prata AM, Barbosa CM, Leles JS, de Sá VC. Estresse ocupacional. Minas Gerais; 2011 [cited 2011 May 18]. ������������������������������������� Available from: URL:http://pt.scribd. com/doc/55485771/Estresse-Ocupacional.

20. Ramirez AJ, Graham J, Richards M, Cull A, Gregory W. Mental health of hospital consultants: the effects of stress and satisfaction at work.

Lancet. 1996;347:724-8.

21. Riveros MP. Relación entre perfil psicológico, calidad de vida y estrés asistencial em personal de enfermería. Rev Univ Psychol. 2005;4(1):63-76.

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Pedagogia em Foco. 2005 [cited 2011 May 18].

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2009;14(3):213-21.

25. Tucunduva LTCM, Garcia ������������������������� AP, Prudente FVB, Centofanti G, Souza CM, Monteiro TA et al.��� A síndrome da estafa profissional em médicos cancerologistas brasileiros. Rev Assoc Méd Bras.

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ISSN: Electronic version: 1984-5685 RSBO. 2013 Jul-Sep;10(3):272-7

Literature Review Article

Cone beam computed tomography and applicability in Dentistry – literature review Fabiana Caroline da Silva1 Ilana Sanamaika Queiroga Bezerra2 Nelson Luis Barbosa Rebellato1 Antonio Adilson Soares de Lima1 Corresponding author: Fabiana Caroline da Silva Rua Augusto Klimmek, n. 508 – Centro CEP 89280-301 – São Bento do Sul – SC – Brasil E-mail: cd_fabiana@yahoo.com.br 1 2

Department of Stomatology, School of Dentistry, Federal University of Paraná – Curitiba – PR – Brazil.

Department of Oral Diagnosis, State University of Campinas – Piracicaba – SP – Brazil.

Received for publication: July 30, 2012. Accepted for publication: January 29, 2013.

Keywords: X-ray computed tomography; radiology; imaging diagnostic.

Abstract Introduction: An appropriate treatment planing is essential for successful rehabilitation in Dentistry. The cone beam computed tomography (CBCT) represents a valuable resource in dental practice because it allows the establishment of a precise treatment plan by means of diagnostic imaging. Objective: To review the literature on CBCT. The history of development of this technique, its benefits and its applicability in different areas in Dentistry will be considered.

Literature review: The CBCT offers advantages over the quality and quantity of anatomical data and promises less distortion of the image with low doses of radiation. It has been established as a valuable technique in the dental specialties. Conclusion: The use of CBCT as a diagnostic method must have precise and appropriate indication to provide adequate cost-benefit effectiveness in the patient’s treatment.

Introduction The adequate treatment planing is indispensable for the rehabilitative success in Dentistry. The evaluation of surrounding dental structures through

imaging resources is one of the prerequisites and it has been used by several dental specialties.

The multiplanar ability of generating images in axial, coronal and sagittal planes are provided by computed tomography (CT), magnetic resonance,

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ultrasound and cone beam computed tomography (CBCT). These semiotics resources enable the professional to recreate the anatomical forms with simple functions increasing the efficacy in diagnosing the clinical cases [2, 12, 20].

Literature review and Discussion CT development dates from the last of 1960s.

However, it was patented by Hounsfield, and British engineer in the year of 1973. The invention promoted an immediate and profound impact in the imaging diagnosis granting him the Nobel Prize in Medicine, in 1979 [21]. From that moment on, the tridimensional imaging provides dramatic changes in medical and surgical practice. With the use of a new technology through the years, the professionals were able to apply this technology for the benefit of the patients [24]. The first generation of CT devices obtained data only in the axial plane of the patient, slice by slice, through a thin beam of x-rays penetrating a single matrix of detectors. In the last three decades, considerable advancements in technology allowed scanning in different planes; currently the scanners have a linear matrix of multiple detectors that obtain several cuts simultaneously, that are “piled up” and reformatted to obtain tridimensional images [21].

CBCT was initially developed for the use in angiography [24, 27]. It is a technique of tridimensional image acquisition developed in the last decades of the past century based on the application of the x-ray beams as conical-shaped centered in image detectors. At the ending, the morphology of the region is reconstructed in 3D by a data set converter by using a modification of the original cone beam algorithm developed by Feldkamp et al. in 1984 [30]. CBCT was previously used by radiotherapy and it has been applied in nuclear, war and spatial industry, in addition to medicine [6]. This technology was introduced in dentomaxillofacial imaging between the years of 1998 and 1999 [8]. A source of conical-shaped ionizing radiation is directed through the middle of the area of interest towards to an area of xray detection at the opposite side. The radiation source and the detector rotate around a fixed fulcrum inside the center of the area of interest.

During the rotation, from 150 to 600 projections of planar sequential images of the field of vision are completely or partially acquired and, following, they are piled up to obtain a 3D representation.

This procedure is different from traditional CT, because it uses a fan-shaped x-ray beam at a helical

progression to acquire individual slices by image.

CBCT comprises the entire field of view (FOV) and, at only one rotation sequence, it is able to acquire sufficient data for reconstruction [27]. The quality images and the resolution capability of CBCT are influenced by some variables including the device type, FOV, voxel size, current and tube voltage and other technical factors [15].

The first CVCT devices were commercially available in 2000 [20]. In USA, the devices started to be used in 2001 [14]. Since that moment, the researches show the use of this technology in Dentistry, so that the scanners have been constantly improved for use in dental offices [20].

CBCT systems commercially available are categorized according to the detector technology and design: a combination of devices coupled to an image intensifier tube or flat screen detector.

This latter exhibits less influence of artifacts which are defined as distortions in images caused by metals, such as those within either restorations or orthodontic brackets [13].

There are four important 3D views: axial, transversal or sagittal, panoramic or coronal a nd the 3D reconstructions. The pa nora mic image reconstructed from the data set of CBCT differs substantially from that produced in the conventional panoramic radiograph and it can be viewed through software for the evaluation of the most comprehensive aspects of the arch [11]. CBCT enables the planing in virtual 3D softwares [6, 13]. The literature has shown that these softwares show the morphology with a clinically significant way and that the primary reconstruction of the data is completed parallely to the occlusal plane, which becomes the landmark. Other authors still affirmed that the reconstructions can also occur at the curve planes and oblique vision [14].

The position of the patient in the CBCT shot for the bucomaxillofacial region is either sitting or standing instead of only supine [6, 13, 27].

The device which demands that the patient lays at dorsal decubitus, occupies a larger area of surface or physical space and it cannot be used for physical impaired patients; also the units where the patient stays standing cannot be adjusted for an adequate height to fit a wheelchair; so devices where the patients stays sitting are more viable and comfortable. However, the head support devices more important than the patient orientation [27].

CB C T i s a l re ady k now n a s mu lt i- sl ice tomography and it is a diagnosis record that currently promises less image distortion without superimposed structures [25]. The technological

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advancements in 3D images offer significant advantages regarding to the quality and quantity of the anatomical data because of the accuracy and proximity with the reality [16].

This technique decreases the “noise”, which can be interpreted as image variations from electronic, artifact or purely stochastic interferences, interposing in the quality and detection of important structures, fact very evident in 2D image [10].

CBCT uses a radiation dose significantly smaller than conventional CT [1, 4, 6, 8, 9, 11, 12, 14, 19, 21, 24, 30, 31]. This technique enables a reduction in the radiation absorbed by the patient because it utilizes a single 360º rotation and a cone beam, while spiral CT comprises several rotations and a fan beam [6, 13]. The radiation dose in CBCT is about 40% smaller than CT, but still 3 to 7 times greater than that of the panoramic radiographic examinations. This fact reinforces that when a 3D image is required, CBCT should be the method of choice [28].

The authors have emphasized the resolutive spatial superiority of CBCT in relation to CT [31].

The voxel size in CBCT can be up to 0.1 mm.

This fact enables the establishment of a resolution greater than CT which reaches only to 0.5 mm [6, 13]. The disadvantage of CT is its high cost and the device size, generally inside hospital environments [6, 21].

CBCT introduction creates new diagnosis resources in Dentistry and it has been established as a valuable technique in bucomaxillofacial, oral surgery and orthodontics specialties [2, 4, 8, 15]. This technology becomes and indispensable diagnosis tool to be applied in different clinical applications, including: evaluation of the receptor site of osseointegrated implants and bone defects; bone graft procedures; evaluation of impacted teeth; orthodontic and endodontic planing; investigation of t he TMJ disorders; procedu res of si nus augmentations and orthognathic surgeries [11].

A compa rat ive st udy reve a led t h at t he identification of cephalometric points used in the orthodontic planing was significantly more accurate with CBCT than with conventional lateral cephalogram [18]. The volume of the airways and respiratory function are highly relevant for this specialty, because different types of malocclusion and nasal obstruction are important etiologic factors for dentofacial anomalies. Obstructive sleep apnea exhibits craniofacial differences such as the size and position of the mandible, enlargement of the posterior air space and tongue and soft palate size. The use of CBCT to evaluate the airways

can provide clinically useful information for the orthodontic treatment [12].

A st udy compa r i n g t he d i rect orona sa l anthropometry with 3D through surface molds created from CBCT in cadavers showed t he superiority of this latter technique. The data set obtained by CBCT was accurate and exhibited an excellent reproducibility compared with the manual method. Additionally, the second method was faster in collecting the data, less invasive and enabled the obtained of a 3D file of the facial morphology of the individual [9].

A study comparing the vertical angulation of all canines of 29 patients at the final phase of the orthodontic treatment concluded that the panoramic radiograph exhibited distortions in the images. This limits its value as a method for assessment of the tooth angulation and mesiodistal angles, which were always greater than those measured through CBCT [25].

The images of the cysts and tumors in the maxillofacial area can provide the bucomaxillofacial surgeon the information necessary for the surgery planing; with an accurate volumetric analysis, the CBCT scanning can predict the need and volume of a potential graft for reconstruction. Although the magnetic resonance examination is considered as the gold standard in the evaluation of the temporomandibular disorders, the condition of the bone components of the joint is offered with excellence by CBCT [24].

CBCT has been considered as an imaging modality very adequate for the assessment of the craniofacial area. It provides clear and accurate images of the structures, and therefore, it is extremely useful for the evaluation of the bone component.

The transversal images can be used for obtaining more information on the appearance, location and path of the root canals and their relationship with other mandibular anatomical structures, including the tooth apexes [3].

Some authors considered CBCT as fundamental to evaluate the position and path of the inferior a lveola r ca na l, ma i n ly i n cases of su rg ica l intervention. This avoids nervous damages such as neuropraxia, axonotmesis and neurotmesis caused by either dilacerations, compression or stretching of the inferior alveolar nerve [7].

The literature suggests that CBCT is more sensible than conventional radiographs regarding to the location of included canines and root resorptions of the surrounding teeth. In 2D projections, a wrong interpretation can occur because of errors caused by projection distortions and blurred images [1]. It is clear the value of the CBCT in the planing of implants,

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surgical evaluation of the diseases, temporomandibular conditions and pre- and post-evaluations of the craniofacial structures [8, 11, 18].

Due to the increase of the requirement for rehabilitation of edentulous mandibles through osseointegrated implants the knowledge of the variations in dimensions and morphology of the endosseous arteries is very important. A study evaluating the distribution of endosseous canals in mandible through CBCT found these structures in 85% of t he pat ients. This fact reinforces t he indicat ion of t his technique in t he preoperative diagnosis, reducing the risk of surgical complications [26].

The literature describes the rich anatomical details provided and the importance of this resource in the surgical planing in Implantolog y. With the advent of CBCT, a valorization of important anatomical structures such as the ma xillary sinuses, lingual and mental foramens, the level of bone resorption in edentulous areas and vascular and surrounding nervous bundles/branches [2].

An in vivo study revealed the success in the preoperative orientation through CBCT in maxillary sinus augmentation and implants installation without transalveolar flap [8].

The traditional radiographs provide adequate i n format ion on t he sites for i nst a l lat ion of osseointegrated implants. However, the limited size of the film, the image distortion, the enlargement and the 2D view generates data and measurement inaccuracy. Thus these factors limit their use [6, 22].

Studies confirmed the existence of the enlargement rate in panoramic radiographs and suggested the CBCT utilization for the pre-operative evaluation in Implantology. CBCT eliminates this limitation and increases the examination accuracy [18, 31].

CBCT avoids the potential complications such as paresthesias, coming from the cortical bone perforation, reaching the inferior alveolar nerve, mental foramen and incisive canal; or seven the bad positioning of the implant inside the bone without the adequate surrounding bone volume, compromising its stability. The cross-sectional image is excellent for defining a cut in which the height and width of the bone can be accurately assessed.

The simulated implants can be positioned into the ideal place for posterior rehabilitation [11].

In Endodont ics, li mited CBCT sca nners capture small volumes that may include only two or three individual teeth. The images obtained eliminate the superimposition of the anatomical structures, such as the roots of the posterior teeth and their periapical tissues. These structures can

be visualized separately at the three orthogonal planes without the superposition of the zygomatic bone, alveolar bone and surrounding structures.

Additionally, the thickness of the cortical plate, the pattern of the bone marrow, presence of fenestrations, inclination and morphology of tooth roots, as well as the number of divergent and convergent canals can be detected. The presence of not identified canals, consequently not treated, it is easily identified at the axial cuts. They cannot be readily seen in the periapical radiographs, even those obtained at different angles [21].

The correct dia g nosis of t he a natomica l variations is important for the success of the endodontic treatment. An in vitro study analyzing the morphology of the root canals in human teeth concluded that the tridimensional image provided

by CBCT is a great advancement as an auxiliary method to establish the endodontic diagnosis [5].

A comparative in vitro study revealed that CBCT accuracy in detecting periapical lesions chemically induced was higher than that from conventional and digital radiographic images. This result is explained by the fact that in an image in layer, the difference between the lesion and its surrounding bone is greater resulting in a better contrast than that of 2D images [29]. Other in vivo study demonstrated that 25.9% of the periapical lesions in the pre-operative period of the apical surgery diagnosed in the CBCT examinations had not been detected by periapical radiographs. These findings once more reinforce the resolutive superiority of CBCT [4].

The authors emphasized that among the disadvantages of the panoramic radiograph are: projection of anatomic structures and differences in the mandibular morphology (like the mylohyoid nerve impression on the mesial surface of the mandible). Thus, they decided to investigate the presence of bifid mandibular canals in a sample of 84 individuals. The results demonstrated that the presence of these canals was detected with statistically significant difference when CBCT and panoramic radiographic images were compared.

This suggests that the cone-beam system improves the diagnosis and prognosis of the clinical and surgical procedures at the retromolar region and mandibular body [17].

The disadvantages associated with CBCT includes the radiation dispersion, the limited dynamics reaching, the minimum detail of the soft tissue, and the presence of the artifacts caused by some dental materials and implants [15].

Some authors believe that the ionizing radiation is the key parameter limiting the use of this

276 – RSBO. 2013 Jul-Sep;10(3):272-7 Silva� et al. – ����� Cone ����� beam ��������� computed ����������� tomography ���� and �������������� applicability in ��� ���������� Dentistry –������������������� literature review

examination and they recommend that at any phase of the treatment one must follow the ALARA principle. ALARA is the acronym for “as low as reasonably achievable”. It is a safe principle for radiation safe aiming to the decreasing of the doses to patients and workers as well as the discard of remnants of radioactive materials employing all reasonable methods [25].

Conclusion CBCT is an excellent diagnosis tool, offering significant advantages regarding to the quality and quantity of anatomic information. When 3D image is necessary, CBCT should be the method of choice always justified by an accurate indication. This will provide an adequate cost/benefit ratio both for the treatment and patient.

References 1. Alqerban A, Jacobs R, Fieuws S, Willems G. Comparison of two cone beam computed tomographic systems versus panoramic imaging for localization of impacted maxillary canines and detection of root resorption. Eur J Orthod.

2011;33:93-102.

2. Angelopoulos C. Cone beam tomographic imaging anatomy of the maxillofacial region. Dent Clin N Am. 2008;52:731-52.

3. Balaji SM, Krishnaswamy NR, Kumar SM, Rooban T. Inferior alveolar nerve canal position among South Indians: A cone beam computed tomographic pilot study. Ann Maxillofac Surg.

2012;2:51-5.

4. Bornstein MM, Balsiger R, Sendi P, Arx T. Morphology of the nasopalatine canal and dental implant surgery: a radiographic analysis of 100 consecutive patients using limited cone-beam computed tomography. Clin �������������������� Oral Impl Res. 2011;22:295-301.

5. Breda P, Ribeiro FC, Bortolotti MGLB, Barroso JM, Junqueira JLC. Análise in vitro da anatomia interna de pré-molares inseridos em mandíbulas humanas por meio de exame radiográfico e tomografia computadorizada cone beam. Rev ���� Gaúcha Odontol. 2011;59(3):405-9.

6. Chan H, Misch K. Dental imaging in implant treatment planning. Implant Dent. 2010;19:288-98.

7. Domínguez J, Ruge O, Aguilar G, Náñez O, Oliveros G. Cone beam computed tomographic analysis of the position and course of the mandibular canal. Rev Fac Odontol Antioq.

2010;22(1):12-22.

8. Fornell J, Johansson L-AO, Bolin A, Isaksson S, Sennerby L. Flapless CBCT-guided osteotome sinus floor elevation with simultaneous implant installation. I: radiographic examination and surgical technique. A prospective 1-year follow-up.

Clin Oral Impl Res. 2012;23:28-34.

9. Fourie Z, Damstra J, Gerrits PO, Ren Y. Accuracy and repeatability of anthropometric facial measurements using cone beam computed tomography. Cleft Palate Craniofac J. 2011;48(5):623-30.

10. Gang GJ, Tward DJ, Lee J. Siewerdsen anatomical background and generalized detectability in tomosynthesis and cone-beam CT. Medical Physics. 2010;37:1948-65.

11. Ganz SD. Cone beam computed tomography– assisted treatment planning concepts. Dent Clin N Am. 2011;55:515-36.

12. Ghoneima A, Kula K. Accuracy and reliability of cone-beam computed tomography for airway volume analysis. Eur J Orthod. 2011 Aug;10:16. Available from: URL:http://ejo.oxfordjournals. org/content/early/2011/08/10/ejo.cjr099.full. pdf+html.

13. Hassan B, Souza PC, Jacobs R, Berti SA, Stelt P. Influence of scanning and reconstruction parameters on quality of three-dimensional surface models of the dental arches from cone beam computed tomography Clin Oral Invest.

2010;14:303-10.

14. Hatcher DC, Dial C, Mayorga C. Cone beam CT for presurgical assessment of implant sites. J Calif Dent Assoc. 2003;31:825.

15. Kamburoglu K, Murat S, Kolsuz E, Kurt H, Yüksel S, Paksoy C. Comparative assessment of subjective image quality of cross-sectional conebeam computed tomography scans. Journal of Oral Science. 2011;53(4):501-8.

16. Lamichane M, Anderson NK, Rigali PH, Seldin EB, Will LA. Accuracy of reconstructed images from cone-beam computed tomography scans. ����� Am J Orthod Dentofacial Orthop. 2009;136(2):156-7.

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17. López-Videla J, Vergara M, Rudolph M, Guzmán CL. Prevalencia de variables anatómicas en el recorrido de lós conductos mandibulares.

Estudio mediante tecnología cone beam. Rev Fac Odontol Univ Antioq. 2010;22(1):23-32. ����������������� 18. Ludlow JB, Gubler M, Cevidanes L, Mol A. Precision of cephalometric landmark identification: cone-beam computed tomography vs conventional cephalometric views. Am J Orthod Dentofacial Orthop. 2009;136(3):312.e1-10.

19. Luk LCK, Pow EHN, Li TKL, Chow TW. Comparison of ridge mapping and cone beam computed tomography for planning dental implant therapy. Int J Oral Maxillofac Implants.

2011;26:70-4.

20. Monsour PA, Dudhia R. Implant radiography and radiology. Aust Dent J. 2008;53:11-25.

21. Patel S, Dawood A, Pitt Ford T, Whaites E. The potential applications of cone beam computed tomography in the management of endodontic problems. Int Endod J. 2007;40:818-30.

22. Peker I, Alkurt MT, Mihcioglu T. The use of 3 different imaging methods for the localization of the mandibular canal in dental implant planning.

Int J Oral Maxillofac Implants. 2008;23:463-70.

25. Rabi G, Gómez B, Ramírez E, Rodolph M, Guzmán CL. ����������������������������������� Ortopantomografía versus cone beam CT em la medición de la angulación mesiodistal de caninos em 29 pacientes em fase final de tratamiento ortodóncico. ��������������������� Rev Fac Odontol Univ Antioq. 2010;21(2):198-207.

26. Romanos GE, Gupta B, Davids R, Damouras M, Crespi R. Distribution of endosseous bony canals in the mandibular symphysis as detected with cone beam computed tomography. Int J Oral Maxillofac Implants. 2012;27:273-7.

27. Scarfe WC, Farman AG. What is conebeam CT and how does it work? Clin N Am. 2008;52:707-30.

28. Silva MAG, Wolf U, Heinicke F, Bumann A, Visser H, Hirsch E. Cone-beam computed tomography for routine orthodontic treatment planning: a radiation dose evaluation. Am J Orthod Dentofacial Orthop. 2008 May;133(5):640.e1-5.

29. Sogur E, Gröndahl H, Baks G. Does a combination of two radiographs increase accuracy in detecting acid-induced periapical lesions and does it approach the accuracy of cone-beam computed tomography scanning? J Endod.

2012;38(2):131-6.

23. Pires CA, Bissada NF, Becker JJ, Kanawati A, Landers MA. Mandibular incisive canal: cone beam computed tomography. Clin Implant Dent Relat Res. 2012;1:67-73.

30. Sur J, Seki K, Koizumi H, Nakajima K, Okano T. Effects of tube current on cone-beam computerized tomography image quality for presurgical implant planning in vitro. Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2010;110:29-33.

24. Queresby FA, Savell TA, Palomo JM. Applications of cone beam computed tomography in the practice of oral and maxillofacial surgery. J Oral Maxillofac Surg. 2008;66:791-6.

31. Yim J, Ryu D, Lee B, Kwon W. Analysis of digital panorama and cone beam computed tomograhic image distortion for the diagnosis of dental implant surgery. J Craniofac Surg. 2011;22:669-73.

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Case Report Article

Preventive and surgical intervention in patient with cerebral palsy – case report Gabriella Siqueira da Matta1 Maurício Barriviera1 Andréia de Aquino Marsiglio1 Cláudia Maria de Souza Peruchi1 Alexandre Franco Miranda1 Corresponding author: Alexandre Franco Miranda Universidade Católica de Brasília – Curso de Odontologia Clínica de Odontologia para Pacientes Especiais – Campus I – QS 07 – Lote 01 – EPCT E-mail�� s�: alexandrefmiranda@hotmail.com / alexandref@ucb.br 1

Department of Dentistry for Special Patients, School of Dentistry, Catholic University of Brasília – Taguatinga – DF – Brazil.

Received for publication: July 20, 2012. Accepted for publication: February 22, 2013.

Keywords: disabled persons; cerebral palsy; oral health; quality of life.

Abstract Introduction: Cerebral palsy is defined as a non-progressive brain disorder of movement and posture. The patient is characterized by mental and motor disabilities, sensory impairments of vision and hearing, besides having seizures and contraction joints. Objective: To address a multidisciplinary dental intervention in a patient, leucoderma, 11 years-old, with cerebral palsy who attended the Special Patients Clinic of the Catholic University of Brasilia, Brazil. Case report: Clinical interventions to promote oral health, emphasizing the responsible guidelines regarding oral hygiene techniques, and surgical procedures such as extractions of deciduous teeth #75, #85, #63 (phase 1) and ulectomy in the region of teeth #24 and #25 (phase 2) were performed. Conclusion: The multidisciplinary assistance targeted to the oral health of the patient with cerebral palsy can be considered as an important strategy for promoting the health and quality of life in this population group.

Introduction Cerebral palsy (CP) is a static brain lesion that may be defined as a non-progressive disorder of movement and posture. It is usually associated with epilepsy, and abnormalities of speech, hearing,

vision and mental retardation, which can be determined by prenatal, perinatal, and postnatal factors ������� [2, 3].

Individuals with cerebral palsy are classified according to the changes of muscle tone and the

279 – RSBO. 2013 Jul-Sep;10(3):278-83 Matta� et al. – ��������������� Preventive and surgical ��������������������������������� intervention in patient ����� with ��������������� cerebral palsy –������������� case report

type of movement disorder that these individuals perform: spastic, athetoid, ataxic, hypotonic, and mixed ������� [4, 8].

The treatment aims palliative and rehabilitative mental and motor skills, however none of them is able to promote a full recovery of these patients [2, 5].

Normally, these patients use anticonvulsant medications, epileptic drugs, which may interfere in oral health as cause gingival hyperplasia associated with the accumulation of biofilm due to the difficulty of performing oral hygiene and reduction in salivary flow ���� [4, 9, ������� 11].

D i��������������������������������������� s e a s e s of t he ora l c av it y t h at a f fe ct these individuals are the same as those in the general population (caries, periodontal diseases, malocclusion, bruxism and enamel hypoplasia), but they occur more frequently in patients with

CP, due to a number of factors associated such as poor oral hygiene, type and consistency of food, use of medications, tonicity of facial muscles, lack of information by the persons responsible for the patient and the lack of access to specialized dental services [12, ��������� 13].

The dentist, doctors and healthcare professionals who treat patients with disabilities play an important role in health promotion and improvement in quality of life for these patients through multidisciplinary clinical planning, as in cerebral palsy patients who need special care [1, ������������ 14, 23].

The aim of this study was to report a clinical case in which preventive and surgical interventions were performed in a child with cerebral palsy attended at the clinic for Special Patients of the Catholic University of Brasilia, Brazil.�

Case report Patient diagnosed with chronic non-progressive encephalopathy (cerebral palsy), 11 years-old, male, was referred to dental evaluation at the Dental Clinic for Special Patients of the Catholic University of Brasília (UCB) for dental assessment because he presented motor disorder and a high degree of dependence in order to perform daily life activities such as correct oral hygiene (figure 1).

Figure 1 – Patient with cerebral palsy at the Dental Clinic for Special Patients of the Catholic University of Brasilia

During the anamnesis, the mother reported that she had observed the presence of gingival bleeding and increase in volume in the region of teeth 24 and 25 because the patient insisted on keeping his hand in his mouth.

The doctor responsible for the patient was asked to provide a report on his present systemic condition, as well as the signing of the informed consent by the legal guardian, his mother, for the development and subsequent implementation of the dental treatment plan.

280 – RSBO. 2013 Jul-Sep;10(3):278-83 Matta� et al. – ��������������� Preventive and surgical ��������������������������������� intervention in patient ����� with ��������������� cerebral palsy –������������� case report

According to the neurological report, the patient presented mental retardation with an undetermined etiology, controlled behavior disorder, symptomatic generalized epileptic syndrome partially controlled by the use of anticonvulsant medications such as clonazepam, ten drops at night; topiramate 50 mg every 8 hours and 100 mg/day of phenobarbital.

At intraoral examination, it was observed the accumulation of biofilm, ogival palate, oroantral communication, anterior open bite, occlusal imbalance, eruption cyst in the region of teeth #24 and #25, semi-erupted teeth #15, #14, #21, #23, #25, #26 and #36, lingual position of the teeth #32 and #42, mesioangular position of teeth #31, #32, #41 and #42 and mobility of teeth #63, #75 and #85.

The panoramic radiograph showed the final stage of rhizogenesis in several teeth; advanced stage of rhyzolysis in teeth #63, #75 and #85; teeth #18, #28, #38 and #48 retained and at the beginning of coronal formation showing an early coronary formation (figure 2).

Figure 2 – Initial panoramic radiograph

Aiming at reducing the amount of biofilm present, low speed prophylaxis was performed with fluoridated prophylactic paste, rubber cup and Robinson brush with the aid of a mouth opener made of wooden sticks and gauze. At this time, the mother received guidance on measures of oral health promotion, and instructions on how to make as well as the correct use of the mouth opener in ��������� order to make easier the patient’s oral hygiene.

After clinical and radiographic analysis, the extractions of teeth #75, #85 and #63 were performed (figures 3A and 3B and 3C) in a single appointment. We performed the antisepsis of the oral cavity with gauze soaked into chlorhexidine 0.12% and then to the extraoral region the antisepsis was performed with topical PVPI. The local anesthetic used was Benzotop® 200 mg / g, infiltrative anesthesia was performed. For the entire process of extracting teeth, 1.5 vials of lidocaine hydrochloride 0.2%, 1:100,000 with adrenaline were used.

Figures 3A, 3B, 3C – A, B. Clinical aspect of tooth #85 with mobility and #75 with fracture; C. Clinical aspect of tooth #63 and swelling of a firm consistency in gingival mucosa (teeth #24 and #25)

281 – RSBO. 2013 Jul-Sep;10(3):278-83 Matta� et al. – ��������������� Preventive and surgical ��������������������������������� intervention in patient ����� with ��������������� cerebral palsy –������������� case report

In the clinical analysis of the region of teeth #24 and #25, it was observed a swelling of a firm consistency, which had an aspect of normality (figure 3C). After the radiographic analysis of the region, the ulectomy surgery was indicated after 15 days. This procedure was carried out following pre-surgical approaches previously reported.

For the surgical procedure, infiltration anesthesia was performed in the middle superior alveolar nerve and complementary anesthesia with infiltrative terminals using two vials of 2% lidocaine with 1:100,000 adrenaline. Subsequently, an elliptical

incision was made with a size 11 scalpel blade on the edge of the fibrous gingival, contributing to immediate exposure of the occlusal surface of the teeth #24 and #25. Compression was performed in the area with gauze soaked into chlorhexidine 0.12% (figure 4). At the post-operative period, paracetamol 200 mg every 6 hours for 3 days was prescribed and the mother was instructed to clean the area with 0.12%chlorhexidine. The biopsies removed during surgery were sent for histopathological examination at the Catholic University of Brasilia, confirming the diagnosis of eruption cyst.

Figure 4 – Clinical aspect after the removal of gum tissue and irrigation with 0.12% chlorhexidine - Exposure of dental crowns (teeth #24 and #25)

One week later, the patient returned for clinical reassessment and the area submitted to surgical intervention was in favorable healing conditions and greater exposure of the coronal region of teeth #24 and #25 (figures 5A, 5B).

Figures 5A, 5B – A. Clinical aspect after removing teeth #63, #75 and #85; B. Clinical aspect 15 days after ulectomy in the region of teeth #24 and #25

For the patient’s comfort, all the procedures were performed while he was sitting in the wheelchair.

282 – RSBO. 2013 Jul-Sep;10(3):278-83 Matta� et al. – ��������������� Preventive and surgical ��������������������������������� intervention in patient ����� with ��������������� cerebral palsy –������������� case report

Discussion Cerebral palsy (CP) describes a group of movement and posture developmental disorders attributed to non-progressive disturbances in the brain of the developing fetus or child causing limitations in daily activities. It is commonly associated with epilepsy, abnormalities of the senses and mental retardation [4, 24] therefore, justifying the need to adopt special, intensive and above all, individual care of patients with cerebral palsy, particularly during preventive and minimal dental interventions [2, 11, 14].

Dental evaluation of the patient with cerebral palsy must be made by careful anamnesis associated with multidisciplinary planning in conjunction with the other health professionals and family members involved [6, 15, 17].

The dentist plays an important role in the quality of life of patients with cerebral palsy, because the problems in the oral cavity may contribute to a poor quality of life of these special patients [10, 18, 25].

These patients have a higher predisposition to diseases of the oral cavity such as caries, periodontal diseases, malocclusion, bruxism and enamel hypoplasia with greater frequency than that in the general population [16, 19, 21, 22, 24], with some features present in the reported case.

According to Maranhão [12], Nallegowda et al.

[14] and Previtali and Santos [16], poor oral hygiene in patients with cerebral palsy is characterized by the inability of these individuals in brushing their teeth and family difficulty in opening their mouths.

Thus, there is a need for guidance and training of those responsible to promote oral health.

Guida nce on t he t y pes a nd frequency of ingestion of food and oral hygiene techniques are important in the routine of patients with cerebral palsy, especially the use of adaptations, such as the use of wooden spatulas to facilitate opening of the oral cavity of a CP, as described in the case report [7, 19, 27].

The main difficulty encountered by dentists today is being able to safely perform clinical procedures in these patients, once cerebral palsy is not a negative condition to treatment. If the treatment is properly planned in a multidisciplinary group, invasive procedures can be performed normally [6, 9, 17].

The dental surgical procedures in patients with cerebral palsy should promote the quality of health of the individual, performed in stages, because these patients cannot stay long in the dental chair.

Importantly, clinical activities should always be done by a well trained staff at four hands, in addition to external support, as reported [1, 15, 26].

It is important to the dentist to have the knowledge on t he systemic condit ion of t he individual with CP, drug interactions and the handling of negative side effects [12, 15, 18].

Several types of physical and mechanical restrictions have been described and used in dental treatment of people with special needs [17], however, no protocol for positioning the patient for ambulatory dental attendance was found, in order to reduce the postural instability caused by the patient’s increased muscular tonus and inhibition of reflexes such as the asymmetry of the tonic reflex of the neck, frequently observed in these patients [2, 14]. However, for the patient’s greater comfort all the procedures reported here were performed while he was sat on his own wheelchair [18, 20].

Some sug gestions should be followed for an adequate clinical attendance, such as: good positioning of the patient, in which the patient is comfortable and does not cause any undesired reflex; the use of immobilizer and mouth openers [17, 20]. The purpose of all these measures and others are focused on the success of treatment and well-being of the special patient [2, 6, 9].

The clinical follow-up of patients with cerebral palsy by the dentist should be continuous, respecting the patient’s real needs, behaviors performed by the family for the maintenance of oral health and clinical procedures performed [19, 25, 26], as described.

The ideal dental attendance for the patient with cerebral palsy is early prevention, especially with the active participation of parents or relatives in the process of introducing oral hygiene care and associated with the specialized ambulatory treatment of these patients [2, 6, 15, 17, 18].

Conclusion It can be concluded that the multidisciplinary approach to execute the oral health care of the patient with cerebral palsy, as reported, may be considered as an important strategy in promoting health and quality of life.

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3. Bax M, Goldstein M, Rosebaun P. Proposed definition and classifications of cerebral palsy. Rev Med Child Neurol. 2005;47:571-6.

4. Costa PHM, Costa MABT, Pereira FM. ���� The clinic-epidemiological profile of patients with cerebral palsy treated in a dentistry center in Distrito Federal, Brazil.��������������������� Com �������������������� Ciências Saúde.

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6. De Oliveira Andrade PM, De Oliveira Ferreira F, Haase VG. Multidisciplinary ���������������������������������� perspective for cerebral palsy assessment after an international, classification of functioning, disability and health training. Dev Neurorehabi���������������������� l. 2011;14(4):199-207.

7. Dougherty NJ. A review o cerebral palsy for the oral health professional. Dent Clin North.

2009;53(2):329-38.

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9. Haddad AS. Odontologia para pacientes com necessidades especiais. ��������������������������� São Paulo: Editora Santos; 2007.

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ISSN: Electronic version: 1984-5685 RSBO. 2013 Jul-Sep;10(3):284-88

Case Report Article

Surgical treatment of transmigration of mandibular canine Ana Maria Estivalete Marchionatti1 Vinícius Felipe Wandscher1 Felipe Wehner Flores1 Jorge Abel Flores2 Corresponding author: Ana Maria Estivalete Marchionatti Rua Floriano Peixoto, n. 1.184 CEP 97015-372 – Santa Maria – RS – Brasil E-mail: anamarchionatti@hotmail.com 1 2

Department of Restorative Dentistry, Federal University of Santa Maria – Santa Maria – RS – Brazil.

Department of Stomatology, Federal University of Santa Maria – Santa Maria – RS – Brazil.

Received for publication: September 10, 2012. Accepted for publication: April 16, 2013.

Keywords: tooth, impacted; surgery, oral; diagnosis.

Abstract Introduction: The occurrence of canine impaction is not a rare phenomenon, but transmigration of the tooth across the midline is a less common event. The finding is normally asymptomatic and the etiologic factors involved in the transmigration process are still unclear. Objective: To present a clinical case of surgical treatment of a transmigrated mandibular canine. Case report: A 17-year-old male patient presented to the dental clinic to remove an unerupted canine. Clinical and radiological examinations led to the diagnosis of a transmigrated canine in the mental region. Surgical removal was the treatment of choice and further radiographs were needed to complement the clinical exam and to determine the location of the tooth precisely for the surgical procedure.

Postoperative period was uneventful. Canine transmigration is a rare finding and symptoms are usually absent. Conclusion: An early detection is important to plan the treatment and mainly to avoid future complications.

285 – RSBO. 2013 Jul-Sep;10(3):289-93 Marchionatti� et al. – Surgical ���������������������� treatment of transmigration ������������������ of mandibular ������������������ canine

Introduction The occu r rence of i mpacted ca n i nes is not uncommon in Odontolog y, a nd cases of mandibular unerupted canines are less frequent than maxillary ones [9]. Recurrently, intraosseous teeth move to a local distant from its origin, but they usually remain in the same side of the arch [6]. A rarer phenomenon is the migration of an impacted canine across the midline without pathological inf luences. This event is known as the term “transmigration” [9] and happens a lmost exclusively in t he ma ndible [2]. It is difficult to determine its incidence, but it ranges approx i mately from 0.33% [5] to 0.48% [2].

Although usually asymptomatic [2], the situation represents functional, aesthetics, orthodontics and surgical problems [13].

A lthough etiolog y of this anomaly is not completely defined, ma ny factors have been suggested to explain the condition. Premature loss of deciduous canine, interferences that delay canine eruption and heredity can be causes of transmigration [13]. Surgical removal, orthodontic alignment and transplantation are some of the available treatment options.

It is proposed t hat to be considered transmigrated, canines should cross the midline at least half of its length [8]. However, it has been suggested that the tendency to migrate across the midline is more important than the distance traveled. Moreover, the distance coursed depends on the stage of transmigration when the condition is diagnosed [9].

This article aims to report a case of surgical treatment of a transmigrated mandibular canine.

Case report A male patient, 17 years old was referred by an orthodontist in order to remove a left canine impacted in the mandible. The patient reported that the tooth was asymptomatic. During intraoral physical examination, it was detected absence of tooth #33. Panoramic radiograph revealed that the mentioned tooth was transmigrated horizontally below the root apices of anterior teeth and both first premolars (figure 1).

Figure 1 – Panoramic radiograph

The treatment consisted of surgical removal of the transmigrated canine. For improved treatment planning, a teleradiography was requested to analyze the precise location of the dental element (figure 2).

286 – RSBO. 2013 Jul-Sep;10(3):289-93 Marchionatti� et al. – Surgical ���������������������� treatment of transmigration ������������������ of mandibular ������������������ canine

Figure 3 – Incision, mucoperiostal flap, osteotomy and exposure of the transmigrated canine

Figure 2 – Teleradiography

After the bilateral anesthesia of mental nerves (2% mepivacaine with 1:10,0000 epinephrine), a straight mucoperiosteal incision was made on the buccal vestibule below anterior teeth and an osteotomy was performed with round burs (figure 3). The canine was extracted in one piece using curved elevators, then the pericoronal f lap was curetted and the area was irrigated with saline solution. Simple interrupted stitches were made internally with absorbable suture 4-0 and, externally, with nylon 4-0 (figure 4).

Sutures were removed after 10 days and the postoperative period was uneventful. Follow-up was made during one year after surgery (figures 5 and 6).

Figure 4 – External suture

Figure 5 – One-year clinical follow-up

287 – RSBO. 2013 Jul-Sep;10(3):289-93 Marchionatti� et al. – Surgical ���������������������� treatment of transmigration ������������������ of mandibular ������������������ canine

Figure 6 – One-year radiographical follow-up

Discussion Canine transmigration is an unusual movement of the tooth that happens almost exclusively in the mandible, although few cases have been reported in the maxillary arch [2].

The finding is generally unilateral [8] and the left side is mostly involved than the right side [5].

Females are more affected than males in a ratio of 1.6:1 [12]. In the present study, the patient was male and the left canine was unilaterally affected.

Transmigration of mandibular canines has not a definite etiology. Some authors have attempted to explain the possible origin of the phenomenon by genetics, trauma, premature loss or retention of the deciduous canine, the long path of canine germ, excessively long crown and agenesis of lateral incisors that may deviate the guide of eruption [2, 9]. Evidences suggest that the bud usually develops in its normal position and then migrates to an abnormal location [9]. Regional disturbances in the dental follicle may cause defective osteoclastic function and form an abnormal eruption pathway [10]. According to Stafne and Giblisico [15], the migration of unerupted teeth is possible due to rich blood circulation and active alveolar bone

formation in the stage of development of the tooth apex. In the case presented in this report, the cause of transmigration is unclear, since the patient did not relate early loss or retention of deciduous teeth nor trauma.

Clinically, the presence of the primary canine and volume in the symphyseal region may suggest an impacted or transmigrated canine [2]. The only sign suggesting the canine transmigration in the case presented in this article was absence of the permanent canine. Radiographs are important auxiliary examinations to determine the diagnosis [1], considering that most cases are asymptomatic.

There are cases that periapical radiographs fail to detect the canine due to its position [5] and occlusal, panoramic or teleradiographies are more suitable to confirm the clinical diagnosis [4, 7]. Early detection is important for a correct planning and avoiding complications, such as the resorption of the roots of adjacent teeth and pathological lesions [7].

Treatment options proposed for transmigrated canines are surgical exposure with orthodontic alignment, transplantation and extraction [2, 3, 6, 7, 14]. Regular follow-up is an alternative when there are no symptoms and anatomical structures could be damaged during interventions [7]. In

288 – RSBO. 2013 Jul-Sep;10(3):289-93 Marchionatti� et al. – Surgical ���������������������� treatment of transmigration ������������������ of mandibular ������������������ canine

these patients, periodical radiographs must be taken in order to avoid future complications [5, 6]. Orthodontic alignment was excluded since the unfavorable position of the canine would make it impossible to bring it to its normal place.

Also transplantation was not possible because there was not enough space in the arch and the apex was closed, with reduced probability of revascularization [11]. Surgical removal was the treatment of choice, in agreement with various studies [4, 7, 12, 13].

When surgical treatment is proposed, care must be taken regarding innervation. Besides performing a nerve block on the migrated side, local anesthesia must also be performed on the side that the tooth belongs, as the canine maintains nerve supply from the original side [6, 7, 9].

5. Buyukkurt MC, Aras MH, Caglaroglu M, Gungormus M. Transmigrant mandibular canines.

J Oral Maxillofac Surg. 2007 Oct;65(10):2025-9.

Conclusion

9. Joshi MR. Transmigrant mandibular canines: a record of 28 cases and a retrospective review of the literature. Angle Orthod. 2001 Feb;71(1):12-22.

Transmigration of mandibular canine is a rare phenomenon and usually asymptomatic. Early detection by means of clinical and radiographic exam has primary importance for improved planning and selection of the most adequate treatment.

References 1. Abuabara A, Cruz GV, Nóbrega MJ. Casual ������� disclosure of an enlargement of the sella túrcica during orthodontic treatment planning. RSBO. 2010 Oct-Dec;7(4):499-501.

2. Aktan AM, Kara S, Akgünlü F, Malkoç S. The incidence of canine transmigration and tooth impaction in a Turkish subpopulation. Eur J Orthod. 2010 Oct;32(5):575-81.

3. Al-Waheidi AMH. Transmigration of unerupted mandibular canines: a literature review and a report of five cases. Quintessence Int. 1996 Jan;27(1):27-31.

4. Alaejos-Algarra C, Berini-Aytes L, Gay-Escoda C. Transmigration of mandibular canines: report of six cases and review of the literature.

Quintessence Int. 1998 Jun;29(6):3995-8.

6. Camilleri S, Scerri E. Transmigration of mandibular canines – a review if the literature and a report of five cases. Angle Orthod. 2003 Dec;73(6):752-62.

7. González-Sánchez MA, Berini-Aytés L, GayEscoda C. Transmigrant impacted mandibular canines: a retrospective study of 15 cases. J Am Dent Assoc. 2007 Nov;138(11):1450-5.

8. Javid B. Transmigration of impacted mandibular cuspids. Int J Oral Surg. 1985 Dec;14(6):547-9.

10. Marks SC Jr, Schroeder HE. Tooth eruption: theories and facts. Anat Rec. 1996 Jun;245(2):374-93.

11. Pacini NM, Nery DTF, Carvalho DR, Junior NL, Miranda AF, Macedo SB. Dental ������� autotransplant: case report. RSBO. 2012 JanMar:9(1):108-13.

12. Peck S. On the phenomenon of intraosseous migration of nonerupting teeth. Am J Orthod Dentofacial Orthop. 1998 May;113(5):515-7.

13. Pippi R, Kaitsas R. Mandibular canine transmigration: aethio-pathogenetic aspects and six new reported cases. Oral Surgery. 2008 Jun;1(2):78-83.

14. Rebellato J, Schabel B. Treatment of a patient with an impacted transmigrant mandibular canine and a palatally impacted maxillary canine.

Angle Orthod. 2003 Jun;73(3):328-36.

15. Stafne EC, Gibilisco JA. Oral roentgenographic diagnosis. Philadelphia: WB Saunders; 1975.

ISSN: Electronic version: 1984-5685 RSBO. 2013 Jul-Sep;10(3):289-94

Case Report Article

Pleomorphic adenoma in the oral mucosa of a young adult: a case report Juliana Andrade Cardoso1 Carla Martins Ferreira1 Mariana Moura de Jesus Fernandes Guerra1 Gleicy Gabriela Vitória Spinola Carneiro Falcão1 Lívia Souza Pugliese1 Jener Gonçalves de Farias1 Corresponding author: Juliana Andrade Cardoso Avenida Praia de Itamaracá, quadra B3, lote 24 – Vilas do Atlântico CEP 42700-000 – Lauro de Freitas – BA – Brasil E-mail: juliandradec@gmail.com 1

Department of Dentistry, Metropolitan Union of Education and Culture – Lauro de Freitas – BA – Brazil.

Received for publication: August 13, 2012. Accepted for publication: January 29, 2013.

Keywords: pleomorphic adenoma; neoplasms; salivary glands.

Abstract Introduction: The pleomorphic adenoma (PA) is the most common benign neoplasia in salivary glands, affecting most commonly the parotid gland of females between the 4th and 6th decades of life.

PA can less commonly affect the minor salivary glands; in these cases the main site of attack is the palate. Objective: This study aims are twofold: to report a clinical case of PA involving minor salivary glands in the oral mucosa, treated conservatively; and to emphasize the importance of pathologic examination in defining the correct diagnosis. Case report: A 22 year-old melanoderm male patient sought emergency room due to asymptomatic swelling in the right side of the face. After comprehensive clinical examination, it was decided to perform an incisional biopsy to confirm the diagnosis and further treatment. After confirming the diagnosis of pleomorphic adenoma, we opted for enucleation of the lesion to avoid possible complications such as scar retraction and salivary fistula.

Conclusion: It is very important that the dentist early diagnoses the neoplasia to perform more conservative treatments and achieve a better prognosis for the patient, always following-up the case for a period from five to ten years to ensure the non-recurrence of this neoplasia.

290 – RSBO. 2013 Jul-Sep;10(3):289-94 Cardoso� et al. – �������������������������������� Pleomorphic adenoma in the oral ���������� mucosa of �� a ������ young �������������������� adult: a case report

Introduction The pleomorphic adenoma (PA) is the most common tumor affection the salivary glands [7, 8], accounting for 33.2% to 89.9% of the cases, followed by carcinomas. [7]. The parotid gland is the most affected [8, 11], followed by the submandibular and minor salivary glands, which have been lesser affected [8]. Considering the minor salivary glands, the palate is the place mostly affected [11].

Clinically, PA of minor salivary glands is a single, solid, smooth, well-delimited structure.

This tumor is composed of a single mass that is encapsulated and consequently shows mobility, except when the lesion occurs in the palate.

Generally, PA is asymptomatic and has a slow development [2, 5, 6, 10].

Some lesions of the salivary glands exhibit similar clinical, histopathological and imaging aspects, which can compose a differential diagnosis of PA [6]. PA may affect the hard palate, which has been the site of most of the malign neoplasias such as adenocarcinoma; and it may affect the parapharyngeal space, a common site for lipoma, therefore limiting and making difficult the diagnosis by clinical aspects. Thus, to obtain a correct differential diagnosis, complementary examinations are required [9, 11].

The ima g ing exa minat ions, such as ultrasonography, computed tomography and magnetic resonance, help in the diagnosis of the lesions because they established their origin, location and limits [9]. Notwithstanding, microscopic examinations are essential to define the diagnosis because they show the histopathological aspects of the lesions differing the sound cells from the tumoral ones [2, 9, 12].

PA early diagnosis enables a more conservative treatment by preventing the bone and tissue infiltration of the lesion l [5]. The election treatment is the surgical excision by resection with a safe margin of 3 to 5 mm [10], because the lesion may relapse frequently according to its location and surgical technique applied. Normally, the post-operative period is uneventful with complete healing by 15 days. The patient must be followed-up for five years.

The appropriate treatment is of extreme importance to reach a good prognosis, therefore avoiding the lesion relapse. A good surgical technique shows a healing rate of 95% [6].

The aim of this study was to report a clinical case of pleomorphic adenoma affecting the minor salivary gland and to discuss its characteristics, emphasizing the important role of the dentist in the correct and early diagnosis of this lesion, resulting in a more conservative treatment and better prognosis for the patient.

Case ������ report A 22-year-old melanoderm, male patient was referred to the clinic of Specialization in Stomatology of the Metropolitan Union of Education and Culture with chief complaint of a swelling in the right side of the face. The patient was accompanied by his parents.

At extraoral physical examination, a facial asymmetry in the right side of the face was observed so that the nasolabial fold disappeared (figure 1).

Figure 1 – A) Extraoral clinical aspect; B) Skull caudal view demonstrating the volume increasing at the right side

291 – RSBO. 2013 Jul-Sep;10(3):289-94 Cardoso� et al. – �������������������������������� Pleomorphic adenoma in the oral mucosa ���������� of �� a young ������ adult: �������������������� a case report

During intraoral physical examination, a tumor lesion could be seen in the buccal mucosa covered by sound tissue, well delimited, with a firm consistency and mobility to palpation. The patient signed a free and clarified consent form. An incisional biopsy under local anesthesia was chosen to define the lesion histopathologically. Firstly, an aspiration puncture was executed aiming to evaluate the lesion type: liquid or solid. No liquids were aspired, so that according to the lesion location and solid aspect the clinical diagnosis proposed was of lipoma (figure 2).

Figure 2 – A) Intraoral clinical aspect; B) Aspiration puncture negative for liquid; C) Incision and divulsion to access the lesion; D) Fragments of the lesion obtained through incisional biopsy

However, the histopathological examination concluded that lesion was a pleomorphic adenoma.

Then, the patient was admitted in the Service of Stomatology and Buccomaxillofacial Surgery of the Holly House Hospital of São Felix, Bahia, Brazil to be submitted to the lesion enucleation under general anesthesia (figure 3).

Figure 3 – A) Incision; B) Divulsion; C) Enucleation of the lesion; D) Surgical sample of 10 x 4 x 7 cm

292 – RSBO. 2013 Jul-Sep;10(3):289-94 Cardoso� et al. – �������������������������������� Pleomorphic adenoma in the oral mucosa ���������� of �� a young ������ adult: �������������������� a case report

The sample was referred to the service of pathological anatomy of the Metropolitan Union of Education and Culture which confirmed the diagnosis of pleomorphic adenoma (figure 4).

Figure 4 – A) Lesion encapsulated (arrow), presenting architectural heterogeneity ; B) Proliferation of the ductal epithelial cells ( white asterisks), involved by myoepithelial cells; C) Presence of abundant myxoid stroma; D) lipomatous differentiation (empty triangles) Images acquired from a digital lamina by using ImageScope software version 11.0.2.725 – Aperio Tecnologies. Hematoxylineosin staining

After fifteen days, the post-operative period was uneventful and the sutures were removed, but there was still a little face asymmetry due to the residual swelling (figure 5).

Figure 5 – Clinical aspect after 15 days

293 – RSBO. 2013 Jul-Sep;10(3):289-94 Cardoso� et al. – �������������������������������� Pleomorphic adenoma in the oral mucosa ���������� of �� a young ������ adult: �������������������� a case report

After 8 post-surgery months, the patient exhibited no signs of lesion relapse and good face symmetry (figure 6). The patient is still undergoing 1-year follow-up in the clinic of Specialization in Stomatology for at least 5 years.

Figure 6 – A) Extraoral clinical aspect after 8 months; B) Skull caudal view after 8 months; C) Intraoral clinical aspect after 8 months

Discussion According to previous studies, PA occurs most frequently in the parotid gland, followed by submandibular glands and less frequently the minor salivary glands [8, 11]. The area main affected by PA of minor salivary glands is the hard and soft palate, corresponding from 42.2% to 55% of the cases, followed by the lips with 14% to 18.5% of the cases and oral mucosa in 15% of the cases [1, 2, 7, 9]. PA predominantly occurs in Caucasian females between the 4th and 6th decades of life aging from 43 to 46 years in average [1, 2, 4, 7, 9, 13]. This aspect differs from those of this present case report in which PA occurred in a melanoderm male patient at the third decade of life. During the intraoral physical examination, clinical aspects similar to those reported in the literature were observed, such as single submucosal tumor lesion of firm consistency and with mobility to palpation [2, 5, 6, 10].

The histopathological examination confirmed the diagnosis of PA because of the abundant and heterogeneous presence of myoepithelial cells in tubular arrangement, glandular epithelium with ductiform structures, and with transformation of the stroma by exhibiting a myxoid and adipose tissue, which is in agreement with the aspects previous reported in the literature [2, 9, 12].

Because the buccal mucosa is not a very common site of PA appearance [3], and the patient was a young melanoderm male adult, facts that disagree with the literature [1, 2, 4, 7, 9, 13], the first diagnosis option suggested in this present case report was of lipoma.

By reviewing the literature, the treatment recommended is the surgical excision by resection with a safe margin from 3 to 5 mm [5, 6, 10].

Notwithstanding, in this case report, an enucleation was chosen because the lesion showed great dimensions, therefore avoiding some complications as scar retraction and salivary fistula. Thus, it is necessary to perform a careful following-up of at least five years because of the probability of relapse.

Conclusion Because PA is a neoplasia with great diversity of cells in constant process of transformation, it demands a correct surgical procedure with safe margin to assure that the surgical site is free of tumoral cells.

It is worth emphasizing the important role of the dentist in executing the early diagnosis of the neoplasia to conduct more conservative treatments and obtain a better prognosis for the patient, always following-up the case for a period from five to ten years to ensure the non-recurrence of this neoplasia.

References 1. Bettio A, Salgado G, Azevedo-Alanis LR, Machado MAN, Grégio AMT, Lima AAS. Prevalência das lesões de glândulas salivares em laudos histopatológicos do Laboratório de Patologia Experimental da PUCPR. RSBO. 2009 Sep;6(3):231-6.

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2. Boros FL, Júnior JB, Boros FL, Boros LH, Silva PA. Adenoma pleomórfico de glândula salivar menor do palato. Odontologia Clín-Científ. 2004 Jan-Apr;3(1):67-72.

3. Dalati T, Hussein MR. Juvenile pleomorphic adenoma of the cheek: a case report and review of the literature. Diagn Pathol [serial online] 2009 Sep;4(32):[5 screens] [cited 2012 Oct 19]. Available from: URL:http://www.diagnosticpathology.org/ content/4/1/32.

4. Jorge J, Pires FR, Alves FA, Perez DE, Kowalski LP, Lopes MA et al. Juvenile intraoral pleomorphic adenoma: report of five cases and review of the literature. Int ��������������������������������� J Oral Maxillofac Surg. 2002 Jun;31(3):273-5.

5. Lacerda SA, Socolowski F, Rosa AL, Ferraz MP, Brentegani LG. Adenoma pleomórfico intraósseo no maxilar: relato de caso clínico. Rev Bras Estomatol. 2005;2(4):5-8.

6. Lawall MA, Simonato LE, Ribeiro ACP, Crivelini MM, Moraes NP. Adenoma pleomórfico: relato de caso clínico. Rev Odontol. 2007 SepDec;19(3):336-40.

7. Loiola RS, Matos FR, Nonaka CFW, Lopes FF, Cruz MCFN. Perfil epidemiológico das neoplasias de glândulas salivares diagnosticadas em São Luís-MA. J Bras Patol Med Lab. 2009 Oct;45(5):413-20.

8. Rao PK, Shetty SR, Hegde D. Ectopic pleomorphic adenoma. N Am J Med Sci. 2012 Apr;4(4):190-2.

9. Ribeiro-Rotta RF, Cruz ML, Paiva RR, Mendonça EF, Spini TH, Mendonça AR. O papel da ressonância magnética no diagnóstico do adenoma pleomórfico: revisão da literatura e relato de casos. Rev Bras Otorrinolaringol. 2003 Sep-Oct;69(5):699-707.

10. Santiago LM, Torres BCA, Andrade MC, Silva UH, Santana AF, Santos EV. Adenoma pleomórfico em lábio superior. Odontologia Clín-Científ. 2005 Jan–Apr;4(1):63-70.

11. Sharma Y, Maria A, Chhabria A. Pleomorphic adenoma of the palate. Natl J Maxillofac Surg. 2011 Jul;2(2):169-71.

12. Teixeira JM, Cornélio SS, Grillo JPF, Pontes JRM, Ramos MEB, Israel MS. Adenoma pleomórfico en labio superior: relato de caso. ����� Acta Odontol Venez. 2007 Sep;45(3):440-2.

13. Wang D, Li Y, He H, Liu L, Wu L, He Z. Intraoral minor salivary gland tumors in a Chinese population: a retrospective study on 737 cases.

Oral Surg Oral Med Oral Pathol Oral Radiol Endod.

2007 Jul;104(1):94-100.

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1

3.2 – Article’ file

Title of the article: in Portuguese and English – 14 point font size, capital letters.

Abstract: In a single paragraph it must summarize what was done in the following items: Introduction, Objective, Material and methods (case report or literature review), Results and Conclusion.

• Keywords: 3 expressions that identify the content of the article.

The DeCs (Health Sciences Descriptors) should be considered to do so, available at Bireme’s site: http://www.bireme.br.

• Articles in English DO NOT NEED title, abstract and keywords in Portuguese.

• Articles in Spanish need to present title, abstract and keywords in English.

• The following items must appear: introduction, material and methods, results, discussion, conclusion and references.

• Names of registered medicines and materials, as well as commercial products, must appear in parentheses only once (at the first time) after being reported.

References: PAY CAREFUL ATTENTION TO THIS ITEM, SINCE THE ARTICLES WILL BE RETURNED IN CASE THE REFERENCES ARE NOT ACCORDING TO THE RULES. • References must be listed in alphabetical order of names, with lowercase letters, in ascending order.

• When indicating the references within the text, the number of the list of references must be put in brackets (the name of the authors and date of publication may be added). In case there are two authors, both should be quoted by using the conjunction “and”.

• With regards to the list of references, if there are more than six (6) authors the name of the first six authors must be quoted followed by et al.

• When citing journals in the references, they should be abbreviated according to Index Medicus, available at www.nlm.nih.gov. In case of national journals, Bireme’s site must be considered for this search: http://www.bireme.br.

• Periodicals: Wilcox LR. Thermafill retreatment with and without chloroform solvent. J Endod. 1993 Feb;19(4):563-6.

Wilcox LR, Juhlin JJ. Endodontic retreatment of Thermafill versus laterally condensed gutta-percha. �������� J Endod. 1994 Jul;20(6):115-7.

Baratto Filho F, Ferreira EL, Fariniuk LF. Efficiency ������������������������������������� of the 0.04 taper ProFile during the re-treatment of gutta-percha-filled root canals. Int ����������� Endod J. 2002 Ago;35(8):651-4.

• Books: Soares IJ, Goldberg F. Endodontia técnica e fundamentos. 1. ed. Porto Alegre: Artmed; 2001. p. 201-5.

• Articles from the internet: Morse SS. Factors in the emergence of infectious diseases. Emerg Infect Dis [serial online] 1995 Jan-Mar [cited 1996 Jun 5]; 1(1): [24 screens]. Available from: URL:http://www.cdc.gov/ncidod/EID/eid.htm.

QUOTES TO ABSTRACTS, CHAPTERS OF BOOKS, ARTICLES IN PRESS, DISSERTATIONS AND THESIS WILL NOT BE ACCEPTED ANYMORE. The RSBO journal is available for free in the following electronic address: www.univille.br/rsbo.

Non-native and native English speaker authors who would like writing assistance before paper submission may contact RSBO’s official translator for editing/translation service. All services are paid for and arranged by the author, and use of these services does not guarantee acceptance or preference for publication.

RSBO’s official translator contact: Luciana Lourenço Ribeiro Vitor DDS/Pedodontist llribeiro_3@hotmail.com