In-Office Bleaching During Orthodontic Treatment

CLINICAL ARTICLE

In-Off|ce Bleaching During OrthodonticTreatment

MAURICIO NEVES GOMES, DDS, MSc, PhD*, HELIO DUTRA, DDS†, ALEXANDRE MORAIS, DDS, MSc‡, § GUARACI DEVITO-MORAES, DDS, MSc, PhD{ RICARDO SGURA, DDS, MSc, PhD , ANDRE

ABSTRACT Objective: To demonstrate that it is possible to pursue teeth whitening treatment protocols during orthodontic treatment with no esthetic loss.

Clinical Considerations: Many patients undergoing orthodontic treatment desire to have a straight and well aligned dentition, but also whiter teeth.For many years, it was believed that carrying out a whitening treatment with positioned orthodontic brackets in place would result in localized spots on the enamellabial surfaces of teeth.

However, a deeper understanding of the bleaching process suggests thatthe oxidation caused by products, which results from hydrogen peroxide decomposition, are able to diffuse peripherally into the tooth structure and reach even that under the cemented brackets.Two in-off|ce-bleaching treatments were performed in patients using orthodontic f|xed braces in two or three 40 -minute sessions using a 35% hydrogen peroxide.

Conclusion: In-off|ce bleaching is possible and effective, even with orthodontic brackets in position.The teeth were successfully bleached despite the presence of brackets. All biological criteria have been fulf|lled satisfying patients’ expectations of aligned and whitened teeth in less time than if treatments had been performed separately, with satisfactory results and no esthetic loss.

CLINICAL SIGNIFICANCE The whitening ofteeth is possible during orthodontic treatment with f|xed braces without any esthetic loss.The in-off|ce bleaching treatment with bracketsin position also may act as a motivation factor, preventing patient withdrawal or treatment interruption.Therefore, atthe end ofthe orthodontic treatment, the patient is able to display an aligned, functional and whitened smile.

INTRODUCTION One of the reasons that determine the decision of patients to under orthodontic treatment is the desire for a harmonious and aligned smile, aiming to satisfy the esthetic preferences present in modern society.

However, the use of fixed orthodontic appliances, particularly in young patients, contributes to greater

accumulation of plaque and stain deposition on teeth surfaces.1 Dental professionals have generally believed that a whitening procedure during orthodontic treatment would not be viable due to the presence of brackets, which could jeopardize the peroxide diffusion into labial surfaces of the teeth.2,3 Therefore, the whitening

*Dental Materials, USP^University of S~ ao Paulo, Specialist in Dentistry^CETAO, Brazilian Air Force Dentist^NUHFASP, APCD- Paulista Dental Association, S~ao Paulo, Brazil

UMC^University of Mogi das Cruzes, APCD^Paulista Dental Association, S~ ao Paulo, Brazil

`

Dentistry, UNG^University of Guarulhos, APCD^Paulista Dental Association, S~ ao Paulo, Brazil Dental Materials, USP, University of S~ ao Paulo Discipline of Dental Materials, School of Dentistry, UNINOVE^University Nove de Julho, S~ ao Paulo, Brazil

‰

Dental Materials, USP, University of S~ ao Paulo, APCD^Paulista Dental Association, S~ ao Paulo, Brazil Discipline of Dental Materials, School of Dentistry,

UNINOVE^University Nove de Julho, S~ ao Paulo, Brazil

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treatment was usually done after orthodontic treatment, when bracket removal would allow bleaching agents to better access the facial surfaces of the teeth.

In 1990, Haywood and colleagues reported that bleach travels laterally by diffusion even under existing restorations.4 Additional, more recent research also has concluded that the hydrogen peroxide and its byproducts resulting from its decomposition are able to diffuse laterally through the tooth structure even in the presence of a fixed orthodontic appliance.5–7 Despite these scientific findings that demonstrate the diffusion capacity of bleaching agents, there is still some concern among professionals regarding the effectiveness of bleaching on bracketed teeth.

Therefore, they are inclined to wait until the orthodontic treatment is concluded before starting the bleaching treatment.

This article reports two cases of bracketed-teeth bleaching. Hydrogen peroxide, the whitening active ingredient, decomposes releasing active oxygen, which diffuses through the tooth structure, owing to its low molecular weight.8 Thus, oxygen molecules do interact with the staining pigment molecules, even in the enamel area under the bonded bracket.9–11 In addition to the discussion regarding the bleaching agents diffusion capacity, another issue lies in the influence of hydrogen or carbamide peroxides on the bond strength of the bracket/enamel adhesive interface. It is well known that the released oxygen may interfere with adhesive or composite material polymerization.12 It is important to verify whether peroxides may harm the adhesive interface, as it would contraindicate the bleaching treatment during orthodontic therapy. Many studies found in literature have evaluated the bond strength of brackets on whitened teeth, although there are no studies showing the influence of hydrogen peroxide in brackets already bonded to tooth structure.13–15 It is noteworthy that the whitening therapy during orthodontic treatment is not necessary. Instead, it is an

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elective procedure, which refers solely to the esthetic satisfaction of patients. However, the population’s esthetic demands are increasing and justifying this procedure. As an example of this esthetic trend, many patients have been opting for ceramic brackets rather than metallic ones. In cases in which patients seek esthetic options, the whitening therapy performed with brackets in position is a viable option. The esthetic desires of patients should not be disregarded, as many treatments and materials are available to meet this demand.

The bleaching procedure on teeth with brackets will shorten overall treatment time and the patient will have his/her teeth whitened before orthodontic treatment conclusion. In addition, the hydrogen peroxide helps control plaque and reduces gingivitis or periodontal diseases during the use of orthodontic fixed appliances.16

CLINICAL CASE 1 J.F., 17 years old, female, from Campo Grande, MS, Brazil, was submitted to orthodontic treatment with fixed appliances at Associaç~ao Paulista de Cirurgi~ oesDentistas (APCD-Central, S~ao Paulo, Brazil) and inquired her dentists about the possibility of a concurrent teeth-whitening treatment.

The purpose of the orthodontic treatment was functional, as the patient presented with dental

FIGURE 1. Initial evaluation with color comparison using VITA Classical Shade guide (D2).

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FIGURE 3. Positioned retractor—Cheek, lip, and tongue.

FIGURE 2. Orthodontic braces—lateral view.

FIGURE 4. Applied gingival barrier. The 35% hydrogen peroxide and gel thickener syringes connected.

FIGURE 5. Bleaching gel on tooth surface around orthodontic braces.

FIGURE 7. Bleached teeth, immediately after brackets removal.

malocclusion and dental crowding. It is also important to mention that the bleaching treatment with hydrogen peroxide prior to device installation could compromise the bond strength of the cement used to fix the brackets in position.

FIGURE 6. Complete removal of bleaching agent with endodontic aspirator and water.

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At the final stage of the orthodontic treatment, the patient again expressed her interest in teeth whitening.

First, dental biofilm and extrinsic stains were removed with a prophylaxis procedure. Despite the prophylaxis, the teeth still presented a yellowish appearance, probably due to more intrinsic stains. A home

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FIGURE 8. Anterior bleached teeth.

FIGURE 9. Front view—Upper incisors. There is no stained surface due to positioned orthodontic braces during bleaching.

FIGURE 11. Clinical result—Smile after bleaching and braces removal.

FIGURE 10. Lateral view—bleached incisors teeth.

FIGURE 12. Final evaluation with color comparison using VITA Classical Shade guide (A1).

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bleaching treatment with 10% hydrogen peroxide using whitening trays was indicated (Opalescence GO, Ultradent, Utah, USA). The choice for pre-fabricated trays instead of the custom whitening trays was made to favor tray adaptation to the dental arch with the presence of brackets. However, the patient did not use the trays daily, as recommended.

The initial teeth shades were determined using a classic shade guide (VITA, Bad Sackingen, Germany). The identified prevalent shade was D2 (Figures 1 and 2).

The teeth shade selection occurred under daylight and with no operative field isolation, so there was no teeth dehydration, which could adversely influence color assessment, giving teeth a lighter appearance.

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CLINICAL CASE 2

FIGURE 13. Final smile.

Prophylaxis was conducted before bleaching gel application. Then, a lip and cheek retractor with tongue depressant (Arc Flex, FGM, Joinville, Brazil) were positioned (Figure 3). A gingival barrier (Topdam, FGM, Joinville, Brazil) was placed on upper and lower arches. The gingival barrier was of a contrasting color with teeth and gingival structures in order to facilitate the identification of any gap, which would allow peroxide contact with the patient tissues.

The bleaching agent used in this case was a 35% hydrogen peroxide (Whiteness HP Blue, FGM, Joinville, Brazil). The peroxide was homogenized with a gel thickener using a syringe and a connector provided by the manufacturer (Figures 4 and 5). After this, the product was applied to the labial surface of the anterior teeth and premolars. The gel was applied in two 40-minute sessions without any use of light source (1-week interval between sessions). The removal of the bleaching agent was performed with an endodontic suction tip. Next, teeth surfaces were rinsed and the barrier was removed.

Six months after the in-office bleaching, the orthodontic treatment was concluded and the brackets were removed (Figure 6). The teeth were evenly whitened. Stains or color differences were not noticeable on labial surfaces or where the brackets had been fixed (Figures 7–11). The final shade was A1 (Figure 12). The bleaching agents were able to permeate throughout the dental tissue structures, ensuring the lightening effect, even in the presence enamel-fixed orthodontic devices (Figure 13).

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M.S., 18 years old, female, from S~ao Paulo, SP, Brazil, was under orthodontic treatment for 2 years and was concerned about her teeth shade. She underwent a home bleaching protocol 1 year before the implementation of fixed appliances, but reported her teeth were still discolored after orthodontic appliances were applied. As there were still about eight more months before orthodontic treatment conclusion, the patient sought bleaching treatment for professional purposes (job interview) despite her orthodontic devices being in place.

The patient reported previous emetic reflex when using home whitening trays, so the office bleaching with 35% hydrogen peroxide seemed a better indication for her treatment (Whiteness HP Blue, FGM Joinville, Brazil). The initial teeth shade was D2 (VITA Classical Shade Guide—VITA) (Figure 14). The prophylaxis and the gingival barrier application followed the same protocol as described for the previous case (Figure 15).

Three 40-minutes sessions were conducted with a oneweek interval between sessions (Figures 16–19). In Figures 20 and 21, it is possible to note the immediate lightening result achieved after gel removal, with the brackets still in position.

After approximately 7 months from the whitening treatment, the orthodontic appliances were removed.

Figure 22 shows teeth from a labial perspective immediately after brackets removal, with the resin cement still noticeable. The resin cement was removed with a carbide bur (KOMET, Lengo, Germany).

Figure 23 shows the bleaching agent diffusion capacity, as the enamel surface presents a uniform shade. Stains or pigments were not present in areas where the brackets were cemented. The final achieved shade (A2) confirms the effectiveness of the in-office bleaching and attests that the presence of cemented brackets did not preclude the bleach distribution along the enamel surface (Figure 24).

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FIGURE 14. Initial evaluation with color comparison using VITA Classical Shade guide (D2).

FIGURE 15. Applied gingival barrier.

FIGURE 16. The 35% hydrogen peroxide and gel thickener syringes connected.

FIGURE 17. The 35% hydrogen peroxide application.

FIGURE 18. The 35% hydrogen peroxide gel on tooth surface.

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FIGURE 19. Removal of the bleaching gel.

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FIGURE 20. Teeth appearance, immediately after removal of the bleaching gel.

FIGURE 21. Final view after in-office bleaching treatment.

FIGURE 23. Appearance 7 months after brackets removal.

FIGURE 22. Front view.

DISCUSSION In order to understand the mechanisms involved in the whitening process under the cemented brackets, the knowledge of enamel morphology and bleaching agent diffusivity are essential. It is well known that the hydrogen peroxide dissolution products are low molecular weight molecules, which easily diffuse into lamellae, grooves, ďŹ ssures, and depression regions present in enamel structures.2

FIGURE 24. Final color comparison between initial and final appearances using VITA Classical Shade guide (D2).

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The tooth enamel is the most mineralized, hence, the hardest tissue in the human body.17 Its thickness in permanent teeth varies, with less thickness in the mesial and distal surfaces and reaching up to 2.3 gm at cusp tips. From a microscopic perspective, the tooth enamel is an inorganic, solid structure, consisting of long and thin hydroxyapatite crystals, forming prisms

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surrounded by a small percentage of organic matrix (1 wt %) and water (2 wt %), as well as porosities. These pores may be located within the hydroxyapatite prisms or between prisms dependent on the crystals arrangement.18 The larger pores are those located in the interprismatic regions.19,20 Pore dimensions also differ according to each tooth and this dimension variation directly influences the treatment outcome. Apart from pore size differences, they usually present a heterogeneous structure21 with constrictions that are formed due to prisms interlacement. After spreading along the compact enamel tissue structure, the bleaching agents reach the amelodentinal junction region, which is of great permeability. This significant permeability results from the presence of dentinal tubules similar to “great aisles” through which the bleaching agents may easily spread.

The closer to the pulp chamber the tubules are located, the greater their diameter and the higher is the region permeability.

Hydrogen peroxide molecules have already been found in the pulp chamber of teeth after its permeation through enamel and dentin. The presence of hydrogen peroxide molecules in the pulp chamber of bleached teeth was detected by an electric current recognized by microelectrodes placed inside the pulp chamber 15 minutes after gel application.22 The study of Schiavoni and colleagues (2006) demonstrated that successive applications of bleaching gel on tooth surface decreases the time needed for the peroxide molecules to reach the pulp chamber, revealing an increase in permeability of post-bleaching teeth. This is because the peroxide cleaves to salivary proteins and to other high molecular weight substances deposited within dental tissues.23 Therefore, the bleaching agent spreading through enamel pores and their diffusion into the dentinal tubular structure elucidate the well-succeeded whitening therapy conducted in teeth with orthodontic devices. The hydrogen peroxide’s free radicals are able to move in all directions through the dental structure under the bracket cementation adhesive interface. They break the organic stain molecules present all over the teeth labial face.1

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Macroscopically, this study’s observations are confirmed by other clinical studies, which proved that patients who used the whitening tray with 8% hydrogen peroxide for 45 minutes/day during 10 days had their teeth completely whitened despite the presence of brackets during treatment.1 The whitening treatment could be conducted after the orthodontic devices removal at treatment end. Nonetheless, having the teeth bleached during the orthodontic treatment resulted in a motivational factor, which contributed to the patient’s confidence in achieving a harmonious smile with white and aligned teeth. The appearance of bleached teeth also served, in case 2, as a motivational factor and contributed to positive social and professional aspects of the patient’s life (bleaching before a job interview). All these reasons justified and defended the combined treatment.

There is still little clinical/scientific evidence about the efficacy of the whitening treatment in patients wearing orthodontic brackets. The clinical cases reported in this article corroborate the few available studies. The orthodontic treatment is usually long. The possibility of simultaneous teeth whitening with orthodontic treatment increases the patients’ expectations, as teeth will be white and aligned at the end of both treatments. The associated treatment also saves time. The whitening treatment may take up to 2 months for best results achievement.

Therefore, clinical costs may also be reduced In case 2, the office bleaching technique with 35% hydrogen peroxide was conducted, but the home bleaching technique with the carbamide peroxide or hydrogen peroxide in lower concentrations could also be used with the benefit of biofilm control due to the extended time the peroxide is in contact with the teeth.

Most patients who are undergoing orthodontic treatment are children or teenagers with dental morphology, which favors peroxide diffusion, and with a large pulp chamber.24 The use of whitening agents in these patients should be conducted very carefully.

Some authors consider it a contraindication to perform bleaching treatment in patients with orthodontic appliances in the following situations: (i) children or

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youth presenting teeth at different maturation or mineralization stages, which would result in different final colors among whitened teeth; (ii) patients with intruded tooth or teeth covered by gums at unreachable regions. According to these authors, these teeth would not be reached by the whitening agent.2 The acid pH of some whitening agents may oxidize the enamel’s small protein content, which may result in enamel cohesive fracture during brackets removal.2 However, little evidence is available to corroborate this finding.

3.

4.

5.

6.

Finally, not understanding all the whitening procedure microscopic mechanisms should not invalidate or disqualify the association of the whitening/orthodontic treatments.

The clinical evidence is clear and promotes an important treatment plan option to patients and professionals, which may result in higher levels of overall satisfaction.

7.

8.

9.

CONCLUSION Whitening agent diffusion through the dental tissue microstructures of teeth allows whitening procedures during orthodontic treatment with satisfactory results.

It is possible to achieve effectively whitened teeth even in the presence of orthodontic brackets.

10.

11.

12.

DISCLOSURE AND ACKNOWLEDGMENTS The author does not have any financial interest involving the companies and materials mentioned/used in this case report.

The authors thank Ana Paula Taboada Sobral, management consulting of FGM.

2.

Jadad E, Montoya J, Arana G, et al. Spectrophotometric evaluation of color alterations with a new dental bleaching product in patients wearing orthodontic appliances. Am J Orthod Dentofacial Orthop 2011;140:43–7.

Consolaro A, Consolaro RB, Francischone L. Clarifications, guidelines and questions about the dental bleaching

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14.

15.

16.

REFERENCES 1.

13.

DOI 10.1111/jerd.12276

17.

18.

“associated” with orthodontic treatment. Dental Press J Orthod 2013;18:4–10.

Lunardi N, Correr AB, Rastelli AN, et al. Spectrophotometric evaluation of dental bleaching under orthodontic bracket in enamel and dentin. J Clin Exp Dent 2014;6:e321–6.

Haywood VB, Leech T, Heymann HO, et al. Nightguard vital bleaching: effects on enamel and surface texture and diffusion. Quintessence Int 1990;21:801–4.

Dezotti MS, Souza MH, Jr, Nishiyama CK. Evaluation of pH variation and cervical dentin permeability in teeth submitted to bleaching treatment. Pesqui Odontol Bras 2002;16:263–8.

Palo RM, Palo I, Bonetti-Filho MC, et al. Quantification of peroxide ion passage in dentin, enamel, and cementum after internal bleaching with hydrogen peroxide. Oper Dent 2012;37:660–4.

Kwon SR, Wertz PW. Review of the mechanism of tooth whitening. J Esthet Restor Dent 2015;27:240–57.

Kawamoto K, Tsujimoto Y. Effects of the hydroxyl radical and hydrogen peroxide on tooth bleaching. J Endod 2004; 30:45–50.

Feinman RA, Madray G, Yarborough D. Chemical, optical, and physiologic mechanisms of bleaching products: a review. Pract Periodontics Aesthet Dent 1991; 3:32–6.

Rotstein I, Dankner E, Goldman A, et al. Histochemical analysis of dental hard tissues following bleaching. J Endod 1996;22:23–5.

Kwon SR, Li Y, Oyoyo U, Aprecio RM. Dynamic model of hydrogen peroxide diffusion kinetics into the pulp cavity.

J Contemp Dent Pract 2012;13:440–5. do Rego MV, dos Santos RM, Leal LM, Braga CG. Evaluation of the influence of dental bleaching with 35% hydrogen peroxide in orthodontic bracket shear bond strength. Dental Press J Ortho 2013;18:95–100.

Akin M, Aksakalli S, Basciftci FA, Demir A. The effect of tooth bleaching on the shear bond strength of orthodontic brackets using self-etching primer systems. Eur J Dent 2013;7:55–60.

Mullins JM, Kao EC, Martin CA, et al. Tooth whitening effects on bracket bond strength in vivo. Angle Orthod 2009;79:777–83.

Oztaş E, Ba gdelen G, Kiliço glu H, et al. The effect of enamel bleaching on the shear bond strengths of metal and ceramic brackets. Eur J Orthod 2012;34:232–7.

Lazarchik DA, Haywood VB. Use of tray-applied 10 percent carbamide peroxide gels for improving oral health in patients with special-care needs. J Am Dent Assoc 2010; 141:639–46.

Mjor IAF. Embriologia e histologia oral humana. 6th ed. S~ao Paulo (SP): Panamericana; 1990.

Ying D, Chuah GK, Hsu CY. Effect of Er:YAG laser and organic matrix on porosity changes in human enamel.

J Dent 2004;32:41–6.

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IN-OFFICE BLEACHING Gomes et al.

19. Moreno EC, Zahradnik RT. The pore structure of human dental enamel. Arch Oral Biol 1973;18(8):1063 20. Zahradnik RT, Moreno EC. Structural features of human dental enamel as revealed by isothermal water vapour sorption. Arch Oral Biol 1975;20:317–25.

21. Maung NL, Wohland T, Hsu CY. Enamel diffusion modulated by Er:YAG laser (Part 2). Organic matrix. J Dent 2007;35:794–9.

22. Benetti AR, Valera MC, Mancini MN, et al. In vitro penetration of bleaching agents into the pulp chamber. Int Endod J 2004;37:120–4.

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23. Schiavoni RJ, Turssi CP, Rodrigues AL, Jr, et al. Effect of bleaching agents on enamel permeability. Am J Dent 2006; 19:313–6.

24. Soares DG, Gonçalves Basso F, Hebling J, de Souza Costa CA. Effect of hydrogen-peroxide-mediated oxidative stress on human dental pulp cells. J Dent 2015;43(6):750.

Reprint requests: Mauricio Neves Gomes, Av.Nove de Julho, 3229, Cj1211 ^ Jardins ^ S~ao Paulo/SP,Brazil, ZIPCODE 02011- 000; email: maungomes@gmail.com

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