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Journal Journal of of Osteology Osteology and and Biomaterials Biomaterials

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Journal of Osteology and Biomaterials The official journal of the BioCRA and SENAME Societies

BioCRA Biomaterial Clinical and histological Research Association President Giampiero Massei Deputy-president Alberto Rebaudi Scientific Director Paolo Trisi Secretary Teocrito Carlesi Editor in-chief Paolo Trisi, DDS PhD Scientfic director BioCRA, Pescara, Italy

SENAME The South European, North African, Middle Eastern Implantology and Modern Dentistry Society President Gilberto Sammartino Deputy-president Ahmed M. Osman Scientific Director Paolo Trisi Secretary Faten Ben Amor

Editorial Board

Managing Editor Renato C. Barbacane, MD University G. d’Annunzio, Chieti, Italy

Roberto Abundo, Turin, Italy Mario Aimetti, Turin, Italy Moshe Ayalon, Hadera, Israel Luigi Ambrosio, Naples, Italy Massimo Balsamo, Thiene, Italy Francesco Benazzo, Pavia, Italy Ermanno Bonucci, Roma, Italy Mauro Bovi, Rome, Italy Maria Luisa Brandi, Firenze, Italy Paul W. Brown, Pennsylvania, USA Ranieri Cancedda, Genova, Italy Saverio Capodiferro, Bari, Italy Sergio Caputi, Chieti, Italy Chih-Hwa Chen, Keelung, Taiwan Joseph Choukroun, Nice, France Gabriela Ciapetti, Bologna, Italy Giuseppe Corrente, Turin, Italy Massimo Del Fabbro, Milan, Italy Marco Esposito, Manchester, UK Antonello Falco, Pescara, Italy Gianfranco Favia, Bari, Italy Paolo Filipponi, Umbertide, Italy Pier Maria Fornasari, Bologna, Italy Bruno Frediani, Siena, Italy Sergio Gandolfo, Turin, Italy David Garber, Atlanta, USA Thomas V. Giordano, New York,USA Zhimon Jacobson, Boston, USA Jack T Krauser, Boca Raton, USA Richard J. Lazzara, West Palm Beach, USA Lorenzo Lo Muzio, Foggia, Italy Gastone Marotti, Modena, Italy Christian T. Makary, Beirut, Lebanon

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Journal of Osteology and Biomaterials (ISSN: 2036-6795; On-line version ISSN 2036-6809) is the official journal of the Biomaterial Clinical and histological Research Association (BioCRA) and SENAME Societies. The Journal is published three times a year, one volume per year, by TRIDENT APS, Via Silvio Pellico 68, 65123 Pescara, Italy. Copyright ©2011 by TRIDENT APS. All rights reserved. No part of this journal may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying, recording, or any information and retrieval system, without permission in writing from the publisher. The views expressed herein are those of the publisher or the Biomaterial Clinical and histological Research Association (BioCRA). Information included herein is not professional advice and is not intended to replace the judgment of a practitioner with respect to particular patients, procedures, or practices. To the extent permissible under applicable laws, the publisher and BioCRA disclaim responsibility for any injury and/ or damage to person or property as result of any actual or alleged libellous statements, infringement of intellectual property or other proprietary or privacy rights, or from the use or operation of any ideas, instructions, procedure, products, or methods contained in the material therein. The publisher assumes no responsibility for unsolicited manuscript.

Co-Editor Francesco Carinci, MD DMD University of Ferrara, Ferrara, Italy Associate Editors Gilberto Sammartino, MD DDS University of Naples Federico II, Naples, Italy Assistant Editor Teocrito Carlesi, DDS Secretary BioCRA, Chieti, Italy

Gideon Mann, Jerusalem, Israel Ivan Martin, Basel, Switzerland Milena Mastrogiacomo, Genoa, Italy Anthony McGrath, Santmore, UK Alvaro Ordonez, Coral Gables, USA Zeev Ormianer, Tel-Aviv, Israel Carla Palumbo, Modena, Italy Sandro Palla, Zurich, Switzerland Ady Palti, Kraichtal, Germany Michele Paolantonio, Chieti, Italy Giorgio Perfetti, Chieti, Italy Adriano Piattelli, Chieti, Italy Domenique P. Pioletti, Lausanne, Switzerland Paulo Rossetti, Saint Paul, Brasil Sergio Rosini, Pisa, Italy Ugo Ripamonti, Johannesburg, South Africa Henry Salama, Atlanta, USA Maurice Salama, Atlanta, USA Lucia Savarino, Bologna, Italy Arnaud Scherberich, Basel, Switzerland Nicola Marco Sforza, Bologna, Italy Christian FJ Stappert, New York, USA Marius Steigman, Neckargemünd, Germany Hiroshi Takayanagi, Tokyo, Japan Dennis Tarnow, San Francisco, USA Tiziano Testori, Milan, Italy Anna Teti, L’Aquila, Italy Oriana Trubiani, Chieti, Italy Alexander Veis, Thessaloniki, Greece Raffaele Volpi, Rome, Italy Giovanni Vozzi, Pisa, Italy Hom-Lay Wang, Michigan, USA Xuejun Wen, South Carolina, USA

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Journal of Osteology and Biomaterials

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Journal of Osteology and Biomaterials The official journal of the BioCRA and SENAME Societies

contents Review

analysis of anorganic bovine bone 55 Histological in augmentation procedures: a systematic review of prospective studies Mario Bonino, Francesca Pegna, Ivano Conti, Corrado Agrestini, Alberto Barlattani.

Original articles

of extraction sockets implanted with Calcium 67 Comparision Sulphate NewplasterŽ or spontaneously healed: a histological split mouth study in human Ugo Graziani, Renzo Guarnieri, Nicolò Aldini Nicoli, Milena Fini, Roberto Giardino.

Simplified Osteotome Technique (ASOT): 71 Advanced a new technique for sinus augmentation and simultaneous implant placement in patient with extreme bone atrophy Nicola Marco Sforza, Anna Franchini, Romina Gandolfi, Matteo Marzadori.

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Vertical bone augmentation using bone cores from the mandibular symphysis area. Cases report Alexander Veis, Dimitra Katzouraki,Irodis Barlas, Nickos Dabarakis.

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A simplified technique for horizontal ridge augmentation: a case report with histological and histomorphometric analysis Marco Redemagni, Giuliano Garlini, Giovanna Orsini, Francesca Rossini.

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Histological analysis of anorganic bovine bone in augmentation procedures: a systematic review of prospective studies Mario Bonino, Francesca Pegna*, Ivano Conti, Corrado Agrestini, Alberto Barlattani.

Background and Aim: Anorganic Bovine Bone ( ABB ) has been shown to have osteoconductive properties and no inflammatory or adverse responses as grafting materials used in sinus augmentation or alveolar ridge augmentation procedures. The purpose of the present study was to analyze the histologic and histomorphometric analysis of ABB to assess the degree of reabsorption of the graft material and replacement by new vital bone. Material and Methods: All prospective studies published from 1998 to 2010, in which vertical or horizontal bone defects as well as sinus elevation were grafted by means of ABB, were analyzed. A systematic review included studies in which histological analysis of the new vital bone and the residual ABB particles were conducted. Biopsies had to be performed at least 6 months after grafting. Results of data using ABB alone and ABB with autogenous bone were included. Results: From 1372 articles reviewed, 42 titles were screened and only 15 fulltext publications were identified as fulfilling the inclusion criteria. In all studies the investigation was carried out using a specimen for histologic and histomorphometric analysis through an optical or electron microscopy. The percentages reported on the biopsy perfomed between 6 and 20 months (mean: 13 months) after grafting show that the volume occupied by newly-formed bone varied from 12,44% to 38% ( mean: 24,4% ) and the volume occupied by the residual ABB particles varied from 70,2% to 11% (mean: 32,77%). Conclusions: Within the limits of this study there was evidence that the grafting material takes part in the remodelling process. The long-lasting presence of the ABB particles could be explained by a bonding mechanism that maintains the biomechanical integrity of the bone- biomaterial interface during the remodelling processes. The ABB appeared to be osteoconductive and to support new bone formation in augmentation procedures to facilitate the placement of implants in areas with insufficient bone quantity. (J Osteol Biomat 2012; 2:55-61)

Key words: augmented ridges, bone augmentation, bone regeneration, sinus lift, sinus augmentation, bone substitutes, heterologous bone, bio-oss, histological analysis, histomorphometric analysis, osseointegration. Dipartimento Scienze Odontostomatologiche, Università Tor Vergata, Roma Correspondence to *Dott.ssa Francesca Pegna, Piazza Aldo Moro 36 - Pomezia, 00040 Roma Italy  Email: francesca.pegna@libero.it.

INTRODUCTION Numerous grafting materials have been used for sinus augmentation, including autologous bone, mineralized freeze-dried allograft bone, coralline calcium carbonate, bioactive glass, polyactide-polyglicolide materials, syntetic polymers, calcium sulfate, Anorganic Bovine Bone (ABB) and hydroxyapatite. The grafting materials, which are derived from or composed of tissue involved in the growth or repair of bone, could encourage bone formation in soft tissues or stimulate quicker bone growth in bone implant sites. The success of sinus grafting is dependent primarily on the neovascularization of the graft mass, which is reported to derive mainly from the sinus floor1. Autologous bone graft is considered the gold standard in terms of osteogenic potential, but it as some disadvantages. A limited amount of material is available at the intraoral donor site and the use of an extraoral donor site requires general anesthesia and is often associated with morbidity at the donor site2,3,4. The ABB has shown excellent osteoconductive properties and has promised results in sinus floor augmentation procedures. Morover, it was reported that ABB promoted osteogenesis and showed very low resorbability. Anorganic Bovine Bone is a

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substitute manufactured from bovine bone mineral that has been processed and sterilized for use in intraoral grafting procedures. It is composed of only the mineral portion of bone and has been completely deproteinized and it has from 75% to 80% of porosity and it promotes cellular adhesion, wound healing and the formation of new bone tissue. It has a physical-chemical structure that looks like a human cancellous bone, in terms of its calcium phosphor index and its isomeric crystalline dimensions2,3,5,6,7,8 (Fgures 1-8). ABB is a biologically safe material but also it remains long enough to permit slow apposition of de novo bone formation. It has been widely used and associated with high clinical success rates and the osteoconductive properties of bovine bone act as a scaffold that is essential for bone remodeling3,7,8, 9. The procedure of choice to restore this anatomic deficiencyis maxillary sinus floor elevation (sinus lift), is one of the most common preprosthetic surgeries performed in dentistry today. The aim of this techinque is to elevate the maxillary sinus mucosa and to place the graft material between the mucosa and the sinus floor to increase the bone volume available for implant in the appropriate prosthetic position1,4,7,8,10. Sinus grafting and implant placement can be accomplished either as a onestage (simultaneous) or two-stage (delayed) procedure. This decision is often dictated by the amount of residual crestal bone height. Crestal bone measuring less than 5mm in height is usually considered insufficient to provide adequate mechanical stability for simultaneous placement of an endos-

Journal of Osteology and Biomaterials

seous implant. If it is present less than

5

5 mm, it is generally preferred to delay implant placement by several months after the grafting phase, with this time dependent on the type of graft material, to allow for adequate graft matu1

6

2

7 3

4

8

Figure 1-8. Anorganic Bovine Bone is a substitute manufactured from bovine bone mineral that has been processed and sterilized for use in intraoral grafting procedures. It is composed of only the mineral portion of bone and has been completely deproteinized and it has from 75% to 80% of porosity and it promotes cellular adhesion, wound healing and the formation of new bone tissue.


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ration4,6,9,10. The purpose of the present paper was to report the histological findings from biopsies taken 6 months after the maxillary sinus floor augmentation procedure.

of Oral and Maxillofacial Surger”, “International Journal of Periodontics and Restorative Dentistry”, “Journal of the American Dental Association”, “ Journal of Periodontology”.

Material and Methods The protocol of the present systematic review was set out with the following methods: search strategy, eligibility criteria for study inclusion, screening methods and data synthesis.

Eligibility criteria for Study Inclusion Inclusion Criteria: • English-language publication in the dental literature, based on human subjects. • Smoking and controlled diabetes patients were included.

Search Strategy The search strategy incorporated searching of electronic databases (Medline) up to and including 2010. The following keywords/search terms and their combination (grouped as population/exposure and intervention) limited to clinical studies, were used: “dental implants”, “osseointegrated implants”, “intraoral implants”, “oral implants”, “implant supported prosthesis”, “transmucosal implants”, “immediate implant placement”, “delayed implant placement”, “augmented ridges”, “bone augmentation”, “bone regeneration”, “sinus lift”, “sinus augmentation”, “bone substitutes”, “heterologous bone”, “bio-oss”, “DBBM”, “xenograft”, “ histological analysis”, “ histomorphometric analysis”, “ osseointegration”. The collected articles were published in the journals: “Oral surgery, oral medicine, oral pathology, oral radiology, and endodontics”, “Clinical oral implants research”, “International journal of oral and maxillofacial implant”, “Implant dentistry”, “The international journal of periodontics and restorative dentistry”, “ International Journal of Oral and Maxillofacial Surgery”, “British Journal

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Intervention in which only ABB was used as graft material (also mixed with other matherials). Studies in which histological analysis of the new vital bone and the residual ABB particles were conducted. Studies in which biopsy had to be perfomed at least 6 months after grafting.

Figure 9. Search strategy.

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Esclusion Criteria: • Studies with patients affected by congenital malformations, bone defects following ablation for tumor or osteoradionecrosis. • Patients with uncontrolled diabetes were excluded. Screening Methods A three-stage screening process was performed independently to increase accuracy of the extracted data (Fig. 1). During each stage, all disagreements were resolved by discussion. In cases where consensus on excluding an article was not achieved, the article was included in the next stage of screening. The first stage included the screening of titles to eliminate irrelevant publication and animal studies. The second stage of screening excluded the abstract on the number of patients, the nature of the study-sample, the intervention and the outcome characteristics. The third stage of screening of the full text articles was performed using a predetermined data extraction form to confirm the study eligibility based on the predetermined inclusion and exclusion criteria. Data Synthesis and Analysis: Evidence table was created with the data of the included studies, reporting Grafts, biopsy time, histologic results and clinical evaluations.

Results Included Studies The literary search provided a total of 1372 titles concerning the ABB grafts with or without other graft materials in regeneration procedure in association with implant placement. Following the first stage screening of titles, 42 potentially relevant publications were identified. Independent screening of abstracts (second stage screening) resulted in further consideration of 27 for possible inclusion; in fact 14 studies were excluded because: 13 studies didn’t included Anorganic Bovine Bone as graft materials; 1 study was conducted on animals. Following the third stage screening of full text, only 15 publications were identified as fulfilling the inclusion criteria. Population and Intervention Characteristics/ Surgical Approach: In a total of 222 patients, aged between 46 and 63 years, a sinus augmentation was performed in 186 patients in which only 115 received ABB alone and 71 received ABB with autogenous bone and a ridge augmentation was performed in the remaining patients in which only 6 patients received ABB alone and 30 ABB with autogenous bone. A total of 136 patients received ABB alone as graft material and 86 patients ABB mixed with autologous bone. The biopsy was performed in a time of 6 to 120 months. Histologic Results: The Studies analyzed the percentage of vital bone in the period between 6 and 10 months after the graft that is included between 39,76% to 51,73% while

Journal of Osteology and Biomaterials

this percentage varies from 25,2% to 36,6% after 10 months from grafting. Only few studies showed the percentage of lamellar bone whose value ranges from 4,3% to 21,2%. The Marrow area and the ABB area changed respectively from 25,2% to 54,56% and from 11% to 70,2% related to the type of grafts and the biopsy time. Finally the connective tissue area and the ABB new bone area were respectively from 8,8% to 54,1% and from 34% to 36,6%. Clinical Evaluations: The number of implants positioned were between 3 to 135 and the survival rate of implants from 6 to 12 months are average 96,35%. The survival rate after a period of 6 - 10 months is 96,56% and the survival rate after 1524 weeks from harvesting was 97,2%. Discussions The present systematic review produced only 15 publications of prospective study each describing interventions to increase the sinus with bone grafting and placement of implants simultaneously or after the first surgery. The percentages of histological findings depending on the studies: indeed, while all the studies reported values for the percentage of vital bone, some articles11,12 reported the percentages of lamellar bone whose value changes from 4,3% to 21,2% after 6-8 months to biopsy. In iistologic results, the percentage of marrow area was reported by some studies 6,7,8,11,14,15 in a time between 6 – 10 month changed from 25% to 54,56 % , only in one study 13 the marrow area was calculate after 20 month to biopsy and was 36,6%. ABB area was de-


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Table 1. Histological analysis

scribed by all authors and the percentage changed from 6% to 22% for ABB with autogenous grafts, while the percentage changed from 25,3% to 70,2% for ABB grafts. The Connective tissue area (%) was reported in a few articles 8,11,12 16,17 ranging between 8,8% to 54,1%. Finally the ABB new-bone area (%) 11,17,18, was between 34% to 36,7%. In the clinical evaluations were analyzed, the number of implants placed, the follow-up at the implants position and the percentage of the survival rate of implants: the number of implants

positioned changed depending on the study8, 16,17,19,20,21 and was between from 3 to 135, the follow-up was calculated from 6 to 10 months or 15 to 24 weeks to implants position and the survival rate for the follow-up among from 6 to 10 months is averages 96,39% while was equal to 97,2% after 15 to 24 weeks and only one study21 reported a survival rate to 100% after 12 months of follow-up.

Conclusions The present sistematic review of clinical and istological study has shown: 1) implants placed whit sinus lift or bone regeneration with ABB alone or ABB with autogenous bone; 2) the histological analysis in percetage of the new bone and the grafts residued; 3) the survival rate of implants positionated after grafting. The results of this human study suggest that composite graft represents an important alternative to autografts in sinus floor lift procedures, although autogenous bone

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alone remaines the most predictable material for the sinus lift procedure if its association with ABB show results less predictable than ABB with autogenous bone grafts.5,10,11,13,17 These studies have shown that the ABB has to be highly biocompatible with oral hard tissues in humans and to have the properties of an osteoconductive material and to assess the interrelationship between graft and new bone, and also the potential metabolization of ABB by osteoclasts could be confirmed by the progressive increase in relative bone volume. The increase in osteocytes in the bone around the biomaterial particles could be considered a “bone strategy� to overcome the absence of functional syncytium insiede the biomaterial particles and to make a contribution to strengthening the bone–biomaterial composite. On this basis, the bovine derived bone mineral would seem to be a suitable material for grafting of alveolar defects prior to implant placement. They concluded that Bio-Oss becomes integrated and subsequently replaced by newly formed bone 2,6,7,10,17,18,20,21.

References: 1. Hassani A, Khojasteh A, Alikhasi M, Vaziri H. Measurement of volume changes of sinus floor augmentation covered with buccal fat pad. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2009;107(3):369-74. 2. Traini T, Degidi M, Sammons R, Stanley P, Piattelli A. Histologic and elemental microanalytical study of anorganic bovine bone substitution following sinus floor augmentation in humans. J Periodontol 2008;79(7):1232-40. 3. Mangano C, Scarano A, Perrotti V, Iezzi G, Piattelli A. Int J Oral Maxillofac Implants. 2007 Nov-Dec;22(6):980 Maxillary sinus augmentation with a porous synthetic hydroxyapatite and bovine-derived hydroxyapatite: a comparative clinical and histologic study. 4. Del Fabbro M, Testori T, Francetti L, Weinstein R. Systematic review of survival rates for implants placed in the grafted maxillary sinus. Int J Periodontics Restorative Dent 2004;24(6):565-77. 5. Canullo L, Trisi P, Simion M. Vertical ridge augmentation around implants using ePTFE titanium-reinforced membrane and deproteinized bovine bone mineral (biooss). Int J Periodontics Restorative Dent 2006;26(4):355-61. 6. Froum SJ, Wallace SS, Cho SC, Elian N, Tarnow DP. Histomorphometric comparison of a biphasic bone ceramic to anorganic bovine bone for sinus augmentation: 6- to 8-month postsurgical assessment of vital bone formation. A pilot study. Int J Periodontics Restorative Dent 2008;28(3):27381. 7. Froum SJ, Wallace SS, Elian N, Cho SC, Tarnow DP. Comparison of mineralized cancellous bone allograft (Puros) and anorganic bovine bone matrix (Bio-Oss) for sinus augmentation: histomorphometry at 26 to 32 weeks after grafting. Int J Periodontics Restorative Dent 2006;26(6):543-51. 8. Simion M, Fontana F, Rasperini G, Maiorana C Vertical ridge augmentation by expanded-polytetrafluoroethylene membrane and a combination of intraoral autogenous bone graft and deproteinized anorganic bovine bone (Bio Oss). Clin Oral Implants Res 2007;18(5):620-9.

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9. Galindo-Moreno P, Avila G, FernándezBarbero JE, Aguilar M, Sánchez-Fernández E, Cutando A, Wang HL. Evaluation of sinus floor elevation using a composite bone graft mixture. Clin Oral Implants Res 2007;18(3):376-82. 10. Marchetti C, Pieri F, Trasarti S, Corinaldesi G, Degidi M. Impact of implant surface and grafting protocol on clinical outcomes of endosseous implants. Int J Oral Maxillofac Implants 2007;22(3):399-407. 11. Zitzmann NU, Schärer P, Marinello CP. Long-term results of implants treated with guided bone regeneration: a 5-year prospective study. Int J Oral Maxillofac Implants 2001;16(3):355-66. 12. Hallman M, Cederlund A, Lindskog S, Lundgren S, Sennerby L. A clinical histologic study of bovine hydroxyapatite in combination with autogenous bone and fibrin glue for maxillary sinus floor augmentation. Results after 6 to 8 months of healing. Clin Oral Implants Res 2001;12(2):135-43. 13. Traini T, Degidi M, Sammons R, Stanley P, Piattelli A. Histologic and elemental microanalytical study of anorganic bovine bone substitution following sinus floor augmentation in humans. J Periodontol 2008;79(7):1232-40.

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window: histomorphometric and clinical analyses. Int J Periodontics Restorative Dent 2005;25(6):551-9. 18. Norton MR, Odell EW, Thompson ID, Cook RJ. Efficacy of bovine bone mineral for alveolar augmentation: a human histologic study. Clin Oral Implants Res 2003;14(6):775-83. 19. Proussaefs P, Lozada J, Kleinman A, Rohrer MD, McMillan PJ. The use of titanium mesh in conjunction with autogenous bone graft and inorganic bovine bone mineral (bio-oss) for localized alveolar ridge augmentation: a human study. Int J Periodontics Restorative Dent 2003;23(2):185-95. 20. Mangano C, Scarano A, Perrotti V, Iezzi G, Piattelli A. Maxillary sinus augmentation with a porous synthetic hydroxyapatite and bovine-derived hydroxyapatite: a comparative clinical and histologic study. Int J Oral Maxillofac Implants 2007;22(6):980-6. 21. Pettinicchio M, Traini T, Murmura G, Caputi S, Degidi M, Mangano C, Piattelli A. Histologic and histomorphometric results of three bone graft substitutes after sinus augmentation in humans. Clin Oral Investig 2012;16(1):45-53.

14. de Vicente JC, Hernández-Vallejo G, Braña-Abascal P, Peña I. Maxillary sinus augmentation with autologous bone harvested from the lateral maxillary wall combined with bovine-derived hydroxyapatite: clinical and histologic observations. Clin Oral Implants Res 2010;21(4):430-8. 15. Mangano C, Scarano A, Perrotti V, Iezzi G, Piattelli A. Maxillary sinus augmentation with a porous synthetic hydroxyapatite and bovine-derivedhydroxyapatite: a comparative clinical and histologic study. Int J Oral Maxillofac Implants 2007;22(6):980-6. 16. Valentini P, Abensur D, Wenz B, Peetz M, Schenk R. Sinus grafting with porous bone mineral (Bio-Oss) for implant placement: a 5-year study on 15 patients. Int J Periodontics Restorative Dent 2000;20(3):245-53. 17. Wallace SS, Froum SJ, Cho SC, Elian N, Monteiro D, Kim BS, Tarnow DP. Sinus augmentation utilizing anorganic bovine bone (Bio-Oss) with absorbable and nonabsorbable membranes placed over the lateral

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Comparision of extraction sockets implanted with Calcium Sulphate Newplaster® or spontaneously healed: a histological split mouth study in human Ugo Graziani1, Renzo Guarnieri2*, Nicolò Nicoli Aldini3, Milena Fini3, Roberto Giardino3 Aim: The purpose of this split mouth study was to compare the histological results in healing of fresh human extraction sockets filled with medical grade calcium sulphate (CS) (Newplaster®, Classimplant, Roma, Italy), with fresh extraction sockets left to heal spontaneously. Materials and Methods: Ten patients were selected for a total of 20 healing sites. In each patient test and control teeth were selected not adjacent to one another. One extraction socket in each patient was filled with CS applied with the “stratification technique” and the control extraction socket was left to heal spontaneously. Biopsies from the extraction sites were collected at the time of implant placement. The core area of every section (0.1 mmq) was selected for morphometric analysis. Results: In the coronal sections of CS grafted sites, the average trabecular bone fraction area was 59.2%, in medium size sections it was 56.1% and in the apical sections it was 58.3%. In all the grafted sections selected, connective tissue and foreign material were not found. In the coronal sections of non-grafted sites, the average trabecular bone fraction area was 25.8%, in the medium size sections 42.5%, and in the apical sections was 57.2%. In all the non-grafted coronal sections we found a percentage of connective tissue amounting to 38.5%, while in the middle size and apical sections we did not find the presence of organized connective tissue. Conclusions: the results of our study suggest that CS is a good graft material, preventing extraction socket walls from collapsing if used in a pre-hardened consistency with the “ stratification technique”. (J Osteol Biomat 2012; 2:63-69)

Key words: Extraction sockets, Calcium Sulphate, Human histology.

Private Oral Surgery Practice, Roma, Italy S.C.S. Scientific Consulting Services, Roma, Italy 3 Department of Experimental Surgery, Research Institute Codivilla-Putti, Rizzoli Orthopaedic Institute, Bologna, Italy. 1 2

Correspondence to *Guarnieri Renzo, Roma, Italy Email: renzoguarnieri@gmail.com

INTRODUCTION Healing of injured or lost alveolar bone as a result of trauma or disease, may pose therapeutic problems in implant dentistry because bone defects often fail to heal, or heal with a type of tissue different from the original, with respect to morphology and function. The extraction of a tooth initiates a mechanism of bone resorption which sometimes causes unfavorable conditions for the insertion of implants in an ideal prosthetic position. Controlled clinical studies have documented an average of 4.0 to 4.5 mm horizontal bone resorption following extraction procedures.1,2 Other studies have documented significant dimensional changes in the surrounding alveolar bone following extraction procedures.3,5 The resorption and remodeling process represent a remarkable problem in implant placement, especially in the anterior maxilla where the dimension and morphology of the alveolar ridge cannot properly accommodate implants.4 Many techniques have been suggested to prevent collapse of extraction socket bony walls, including: 1) Membranes6,7 2) Autologous bone grafting8 3) Non-resorbable hydroxyapatite9,10 4) Demineralized freeze-dried bone8,11 5) Calcium phosphate12,13

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6) HTR-polymeric composite14 7) Coralline calcium carbonate15 8) Cancellous porous bovine bone mineral16 9) Bioglasses17 10) Recombinant human osteogenic protein18 The final goal of the grafting procedure is to achieve formation of 100% living bone tissue around the implants with absence of residual foreign graft material. The presence of a reactive tissue able to undergo a sustained state of remodeling may be the ideal condition to maintain osseointegration over time.19 The standard criterion in bone regeneration is still autologous bone thanks to its biological properties. In fact, several studies confirm its superiority to other biomaterials because of its compatibility and osteogenic potential to form new bone by processes of osteogenesis, osteoinduction, and osteoconduction.20 However, it presents several disadvantages, such as, a limited amount of material, a donor site morbidity, and a discomfort for the patient. It is not yet clear which could be the ideal bone grafting substitute material; some histological studies report positive socket healing responses using alloplasts21 and xenografts16; other studies show poor results obtained with DFDBA, bovine bone, and even autogenous bone when implanted into sockets, following tooth extraction.8,12,13,14,16,21,22 CS was one of the first bone substitutes used in orthopedic medicine and dentistry, thanks to its basic properties: it is readily available, easy to sterilize, inexpensive, completely and rapidly reabsorbable, biocompatible, and has

Journal of Osteology and Biomaterials

been shown to be well tolerated by tissues.23-26 Moreover, CS is osteoconductive; in the presence of bone and/ or periostium, it seems that it almost always becomes osteogenic,25,27 leaving a calcium phosphate lattice that promotes osteogenic activity and therefore bone regeneration.28,29 One of the main problems with CS, as reported in previous studies, is the fast resorption trend of the material, averaged from 2 to 4 weeks, which represents a lenght of time too short to achieve good bone regeneration results.30 Nowadays, we have a new formula of pre-hardened CS such as the medical grade calcium sulfate hemihydrate (MGCSH) (Newplaster NP30® and Newplaster NP170®, ClassImplant, Roma, Italia) which can be applied through the “stratification technique” and has a modulated resorption time, in accordance with the regenerative needs.31-33 The aim of this study is to compare histological healing results of fresh extraction sockets filled with MGCSH using the “stratification technique” with fresh extraction sockets left to heal spontaneously. MATERIALS AND METHODs For this split mouth study, 10 patients (6 males, 4 females) with no systemic disorders, ranging in age from 24 to 64, have been selected for a total of 20 healing sites. The subjects had been treated for moderate to advanced periodontitis and at least two teeth in each subject were scheduled for extraction, as a consequence of advanced periodontal and /or endodontic lesions or

root fractures. In each test and control patient, teeth were selected not adjacent to one another. All procedures were explained to the patients before they signed the consent form. Teeth extractions and elevation of a full thickness flap were performed after local anesthesia. In each patient, (Figure 1) one extraction socket was filled with MGCSH using the “stratification technique”; and the other control site (Figure 2) was left to heal spontaneously. A granular and a powder-like mix of MGCSH were applied within the extraction sockets using the “stratification technique”. The first layer of MGCSH (NP30), of cement consistency, was compacted with a dry gauze against the bony walls in order to achieve hemostasis. Subsequent layers of granular MGCSH (NP170) were packed to fill the socket. One last layer of MGCSH (NP 30) was used in the coronal portion of the socket, then mixed with fast set solution to obtain the hardest consistency possible. The flap was then closed and sutured. No attempts were made to completely cover the graft material where the tooth previously protruded throught the soft tissue. Approximately 3 months later, the sites were anesthetized and after incision and flap elevation, the extraction sockets were identified. Using a trephine bur (2.5 mm in diameter and 10 mm in lenght) a bone biopsy was collected. Following removal of the core, osteotomy was completed and an implant was inserted (Biolok Silhouette, Deertfield Beach, FL, USA). Before histological preparation, tissue


Graziani U. et al.

samples were marked to identify their crestal and deep aspect. Samples were fixed in 4% buffered formaldehyde, dehydrated in graded series of alcohols from 50% to 100% and embedded in methylmethacrylate (Merck, Schuchardt, Honenbrunn, Germany). Crosssections of 70 micron were obtained with a Leica SP 1600 diamond saw microtome (Leica Spa, Milan, Italy); then stained with Fast Green, Toluidine blue, and observed with a Zeiss Axioscop microscope (Carl Zeiss, Spa, Arese, Italy) HISTOMORPHOMETRY Histomorphometric measurements were performed in all the stained slides. Only preserved rounded sections were submitted to these examinations. The core area of every section (0.1 mmq) was choosen for morphometric analysis and the area fraction percentage of each component in each section was measured automatically by Kontron KS 300 software (Kontron Electronics, Eiching bei Munchen, Germany). To evaluate bone quality, trabecular bone volume was measured according to the nomenclature approved by ASBMR (American Society of Bone and Mineral Research) RESULTS At 3 months, after surgical re-entry, 9 extractions sockets in the test group, showed a complete new bone formation and 1 socket showed a healing process with 60% bone regeneration; while 4 sockets in the control group, healed with 100% bone formation and 6 sockets healed with 60 % new bone. Radiographical examinations conducted on 8 patients, (test group) showed

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Figure 1. Test site

MGCSH used to fill extraction socket (black arrows)

Re-entry surgery for implant placement 3 months later. On the x-ray MGCSH is no more detectable and the coronal bone level is the same as in the pre-extraction phase. Figure 2. Control site

post-extraction site not-grafted

Re-entry surgery for implant placement 3 months later. No new bone formation in the coronal part of the extraction socket is detectable on x-ray.

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CT Figure 3. Photomicrograph illustrating a specimen of extraction sockets healed with MGCSH. Coronal section showing lamellar bone and bone marrow. No presence of organized connective tissue and foreign graft material. (original magnification X 5, Fast Green Stain)

Figure 4. Higher magnification of Figure. 1 showing absence of organized connective tissue .

CT Figure 5. Photomicrograph illustrating a specimen of spontaneously healed extraction socket. Coronal section showing lamellar bone and bone marrow. Great presence of organized connective tissue (CT).Original magnification X 5 Fast Green Stain

Journal of Osteology and Biomaterials

Figure 6. Higher magnification of Figure 3 showing presence of organized connective tissue (CT).

new trabecular design, while in the control group, the new trabecular design was reported only in 4 patients. The right quantity and quality of new bone allowing fixture placement was reported in each patient scheduled for implant treatment. HISTOLOGIGAL RESULTS (Tab. 1) Grafted sites (Figures. 3,4). In the coronal sections the average trabeculal bone fraction area was 59,2%, in medium size sections it was 56,6% and in the apical sections it was 58.3%. In all the grafted sections we did not report the presence of organized connettive tissue nor foreign material. Non grafted sites (Figures. 5,6). In the coronal sections, the averege trabecular bone fraction area was 25,8%, whereas in the medium size section was 42.5%, and in the apical sections was 57,2%. In all the coronal sections we found a percentage of connective tissue totalling 38.5%, while in the middle and apical sections we did not report the presence of organized connective tissue.

DISCUSSION Formation of 100% living bone within the extraction socket using MGCSH was evidenced at histologic examinations in all the specimens examined in our study. This agrees with other studies supporting calcium sulfate as a bone substitute23,24,25,26,27. The complete absence of grafting material remnants indicate that MGCSH has undergone complete resorption, therefore leading to the formation of new bone. In order to determine the healing process of newly formed tissue in relation to the presence of grafting material and to evaluate the influence of extraction sockets depth on the healing process, cross-sections along tissue cores from the socket sites were executed and examined histomorphometrically. No statistically significant differences emerged comparing the most superficial with the deepest section cuts in the trabecular area. The presence of a great amount of connective tissue reported within the coronal sections of spontaneously healed sockets confirmed the data reported by other histological studies regarding natural healing of extraction sockets in humans; these extraction sockets showing very little osteogenic activity in the superficial bone fraction area where only occasionally osteoblasts were present34. The consistent presence of connective tissue in the coronal aspect seems to be related to tissues competition in the healing process of conventional non-grafted sockets, which heal by secondary intention. The presence of MGCSH during the healing process in the most superficial portion of the socket seems to promote osteogenic activity; no percentage variations of trabeculal bone within the coronal and apical sections were reported in


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the test sites. The best results achieved with MGCSH during secondary intention healing processes were reported in experimental studies conducted by Payne et al35. The authors reported that CS compared with polytetrafluoroethylene and polylactid acid, offers a greater potential for guided bone regeneration in those surgical sites where primary wound healing cannot be obtained. In a wound healing model Becker et al.22 reported that in the presence of inflammation, there was compromised bone formation, most of which was of a woven kind. In the coronal sections of spontaneously healed sockets, we report the presence of connective tissue (38.5+/-8.7%), which instead was not found in the test sites. MGCSH seems to inhibit the down-growth of epithelium, connective tissue and the colonization of the healing area by non-osteogenic cells developing from the flap. These findings are confirmed by Ricci30

who observed that CS occupies the space during the resorption, allowing the new bone to form. Total resorption data regarding the MGCSH are of great importance; no remnants of the material have been reported in any of the histological sections. These findings agree with the results of De Leonardis and Pecora31 and Guarnieri and Bovi32 and Guarnieri et al.33 who reported a total resorption of MGCSH when used in maxillary sinus augmentation. However, questions concerning the ability of CS to have an osteinductive and/or osteoconductive capacity still remain. Yamazaky et al.36 suggested that calcium sulfate may accelerate the rate of mineralisation of the new bone providing a ready source of calcium ions. CS may be osteoconductive, not in itself, but in the presence of bone and/or periostium and almost always becomes osteogenic25,27.

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As summarized by Ruga et al.37, the mechanism of action of CS is complex and not completely understood, however a molecular activation on bone formation control by CS has been demonstrated by activating, on the preribosomial level, a global down-regulation of microRNAm: bone morphogenetic β-protein 1 and 7, transforming growth factor-β, some hormones such a parathyroid hormone and calcitonin-related polypeptide alpha, and bone receptors such as fibroblast growth factor receptor 1, are over-translated. Some clinical difficulties in using CS as graft material have been reported in previous studies27,38 relative to resorption trend of the same and to the fast reduction of mass observed during the first healing period, suggesting that the two phenomena may be linked. The authors introduced some modifications in the operative technique and described it as “stratification technique”.

Table 1. Statistical analysis Trabecular bone fraction area % Coronal sections

Medium sections

Apical sections

Patient

Test

Control

Test

Control

Test

Control

1

58,2

24,8

58,1

42,9

58,6

55,8

2

60,4

25,6

57,9

42,7

57,9

59,1

3

54,8

24,2

55,8

44,8

54,7

53,8

4

59,1

28,4

59,4

40,4

59,1

59,8

5

58,6

30,2

60,1

41,9

58,6

53,6

6

55,8

29,4

58,6

42,1

53,8

54,9

7

51,6

24,2

54,9

43,0

61,6

58,6

8

59,4

23,8

56,8

44,1

55,3

59,4

9

62,2

22,9

53,2

42,2

61,6

60,0

10

62,8

23,8

51,8

41,8

61,8

58,2

59,2

25,8

56,6

42,5

58,3

57,2

3,4190

2,6162

2,7114

1,1235

2,9292

2,7294

Mean S.D. t Student test P

28,9712 14,9935 0,7507 Level of significance 0,0000 Level of significance 0,0000 Level of significance 0,4637 The difference between the observed The difference between the observed The difference between the observed means is significant at p <0.01 means is significant at p <0.01 means is not significant at p <0.01

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They hypothesized that the application of the grafting material in a putty consistency and a careful compacting of the same without voids, minimizes the fast volume reduction of CS, therefore enhancing its regenerative capacity. These hypotheses have been confirmed in an experimental model of Ricci et al.30, who observed that CS keeps the space within the defect during the resorption process, therefore enhancing its regenerative capacity. Guarnieri & Bovi32 and Guarnieri et al.33 also confirmed the importance of the stratification technique when applying pre-hardened CS for maxillary sinus elevation. The above-mentioned technique used in extraction sockets seems to confirm the hypothesis that a careful stratification and dry compaction of pre-hardened granular MGCSH may be effective in reducing the resorption rate and the size of mass contraction during healing, therefore achieving a more complete bone regeneration and providing a longlasting source of calcium ions. Overall, the results of our study suggest that MGCSH is a good graft material to prevent extraction socket walls from collapse, if used in a pre-hardened consistency with the “stratification technique”. Further studies involving a larger number of sites, as well as different sizes of bone defects defined as “non space-making defects” should be conducted in order to determine the effectiveness of calcium sulfate in guided bone regeneration; however, the histological results of our study confirm the osteogenic capability of MGCSH when used in the extraction sockets. AKNOWLEDGMENT This study was sponsored by a grant from ClassImplant, Roma, Italy.

Journal of Osteology and Biomaterials

REFERENCES 1. Lekovic V., Kenney E.B Weinlaender M et Al. A bone regeneration approach to alveolar ridge maintenance following tooth extraction. Report on 10 cases. Journal of Periodontology 1997;68:563-570 2. Lekovic V., Camargo P., Klokkevold P. & Weinlaender M. Preservation of alveolar bone in extraction sockets using bioreabsorbable membranes. Journal of Periodontology 1998;69:1044-1049 3. Newcovsky C.E. & Serfaty V. Alveolar ridge preservation following tooth extraction of maxillary anterior teeth. Report of 23 consecutive cases. Journal of Periodontology 1996; 67:390-395 4. Johnson K. A study of dimensional changes occurring in the maxilla following tooth extraction. Australian Prosthetic Journal 1969a; 14:241-244 5. Johnson K. A study of dimensional changes occurring in the maxilla following closed face immediate denture treatment. Australian Prosthetic Journal 1969b; 14:371-376 6. Becker W. & Becker B.E. Guided tissue regeneration for implants placed into extraction sockets and for implant dehiscences: Surgical techniques and case reports. International Journal of Periodontics & Restorative Dentistry 1990; 10:377-391 7. Wilson T.G. Jr. Guided tissue regeneration around dental implants in immediate and recent extraction sites: Initial observations. International Journal of Periodontics & Restorative Dentistry 1992;12:185-193 8. Becker W., Urist M., Becker B.E. et Al. Clinical and histological observation of sites implantated with intraoral autologous bone grafts or allografts. 15 human cases. Journal of Periodontology 1996;66:1025—1033 9. Scheer P. & Boyne P.J. Maintenance of alveolar bone through implantation

of bone graft substitutes in tooth extraction sockets. Journal of American Dental Association 1987; 114:594-597 10. Bahat 0., Deeb C., Golden T. & Komomyckyj O. Preservation of ridges utilizing hydroxyapatite. International Journal of Periodontics & Restorative Dentistry 1987;7 (6):35-41 11. Becker W., Becker B.E. & Caffesse R.A. Comparison of demineralized freeze-dried bone and autologous bone to induce bone formation in human extraction sockets. Journal of Periodontology 1994;65:1128-1133 12. Mathai J.K., Chandra S., Nair K.V. & Nambar K.K. Tricalcium phosphate ceramics as immediate root implants for the maintenance of alveolar bone in partially edentulous mandibolar jaws. A clinical study. Australian Dental Journal 1989; 33:421-426 13. Gauthier O., Booix D.& Grimandi G. A new injectable calcium phosphate biomaterial for immediate bone filling of extraction sockets: A preliminary study in dogs. Journal of Periodontology 1999;70:375-367 14. Gross J.& Boyne P.J. Ridge preservation using HTR synthetic bone following tooth extraction. General Dentistry 1995;43:470-473 15. Piattelli A., Podda G.& Scarano A. Clinical and histological results in alveolar ridge enlargement using coralline calcium carbonate. Biomaterials 1997;18:623-627 16. Artzi Z., Tal H.& Dayan D. Porous bovine bone mineral in healing of human extraction sockets. Part I. Histomorphometric evaluation at 9 months. Journal of Periodontology 2000; 17:1015-1023 17. Froum S., Cho S.-C., Rosenberg E., Roher M. & Tarnow D. Histological comparision of healing extraction sockets implantated with bioactive glass or demineralized freeze-dried bone allograft: a pilot study. Journal of Periodontology 2002;73:94-102


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18. Cook S.D., Salkeld S.L. & Rueger D.C. Evaluation of recombinant human osteogenic protein -1 (rhOP-1. placed with implant in fresh extraction sites. Journal of Oral Implantology 1995;21:281-289 19. Garretto L.P., Chen J., Parr J.A. & Roberts W.E. Remodelling dynamics of bone supporting rigidly fixed titanium implants: A histomorphometric comparison in four species including humans. Implant Dentistry 1995; 4:235-243 20. Klijn R.J., Meyer G,J., Bronkhorst E.M., et al. A meta-analysis of histomorphometric results and graft healing time of various biomaterials compared to autologous bone used as sinus floor augmentation material in humans. Tissue Eng. Part B Rev. 2010; 16:493.507 21. Froum S. & Orlowsky W. Ridge preservation through alloplast prior to implant placement: Clinical and histological case reports. Practical Periodontics Aesthetic Dentistry 2000 12:393-402 22. Becker W., Clockie C., Sennerby L., Urist M.R. & Becker B.E. Histological findings after implantation of different grafting materials and titanium micronscrews into extraction sockets: Case reports. Journal of Periodontology 1998; 69: 414-421 23. Bell W.H. Resorption characteristics of bone substitutes. Oral Surgery Oral Medicine Oral Pathology 1976; 47:256260 24. Bahn S.L. Plaster of Paris: a bone substitute. Oral Surgery Oral Medicin Oral Pathology 1966; 21:672-681 25. Calhorn N.R., Neiders M.E. & Greene G.W.Jr. Effects of plaster-ofparis implants in surgical defects of mandibular alveolar processes of dogs. Journal of Oral Surgery 1967; 25: 122128 26. Radenz W.H. & Collings C.K. The implantation of plaster of Paris in the alveolar process of dogs. Journal of Periodontology 36:357-363

27. Frame J.W. Porous calcium sulfate dehydrated used as biodegradable bone implant. Journal of Dentistry 1975;3:177-187 28. Scarano A., Orsini G., Pecora G., et al. Peri-implant bone regeneration with calcium sulphate: a light and transmission electron microscopy case report. Implant Dent. 2007; 16:195-203 29. Palmieri A., Pezzetti F., Brunelli g., et al. Calcium sulphate acts on the mRNA of MG63E osteoblast-like cells. J Biomat. Mater. Res. B Appl. Biomater. 2008; 84:369-374 30. Ricci J.T. et Al. Biological mechanisms of calcium sulfate replacement by bone in â&#x20AC;&#x153;Bone Engineeringâ&#x20AC;? Em Squared Incorpored, Toronto, Canada 2000: 333-356 31. De Leonardis D. & Pecora G. Prospective study on the augmentation of the maxillary sinus with calcium sulfate. Histological results. Journal of Periodontology 2000;71:940-947 32. Guarnieri R. & Bovi M. Maxillary sinus augmentation using pre-hardened calcium sulfate. A case report. International Journal of Periodontic & Restorative Dentistry 2002; 22:503-508 33. Guarnieri R, Pecora G., Grassi R. De Luca M. Maxillary sinus augmentation using pre-hardened granular calcium sulfate ( Surgiplaster Sinus). Radiographic and histological study at 2 years. Int J Periodontics Restorative Dent. 2006 Feb;26(1):79-85. 34. Amler M.G., Johnson P.L. & Salmon L. Histological and histochemical investigation of human alveolar socket healing in undisturbed extraction wound. Journal of American Dental Association 1960; 61:93-101 35. Payne J.M., Cobb C.M., Rapley J.W., Killoy W.J. & Spencer P. Migration of human gingival fibroblasts over tissue regeneration barrier materials. Journal of Periodontology 1996;67:236-244 36. Yamazaky, Y., Oida, S.& Akimoto Y. Response of mouse femoral muscle

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to an implant of a composite of bone morphogenetic protein and plaster of Paris . Clinical Orthopaedyc 1998; 234:240-249 37. Ruga E., Gallessio C., Chiusa L, et al. Clinical and histologic outcomes of calcium sulfate in treatment of post-extraction sockets. J Craniofac Surg 2011; 22:494-498 38. De Leonardis D., Pecora G., Della Rocca C., Cornelini R. & Cortesini C. Short-term healing following the use of calcium sulfate as grafting material for sinus augmentation: a clinical report. International Journal of and Maxillofacial Implants 1999; 14:869-878

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Original article

Advanced Simplified Osteotome Technique (ASOT): a new technique for sinus augmentation and simultaneous implant placement in patient with extreme bone atrophy Nicola Marco Sforza 1*, Anna Franchini 1, Romina Gandolfi 1, Matteo Marzadori 2

Positioning implants in the rear area of the upper jaw can often present difficulties due to low bone quantity. In cases where pneumatization of the maxillary sinus can be observed, be it associated with a reabsorption of the alveolar crest or not, performing a maxillary sinus augmentation can be recommended. In 1994, Summers introduced a “transcrestal” approach to the maxillary sinus, employing manual instruments designed by this Author – Summers osteotomes – that compress the bone tissue of the implant site both laterally and apically. Subsequently, other authors introduced a series of changes in Summers’ original technique, as far as implant surface, surgical protocol and the use of instruments such as video X-ray and sinuscopy are concerned. The common aspect between Summers’ technique and the Authors who modified it, is the recommendation to perform the mini sinus lift in alveolar crests with residual dimensions ≥ 5 mm. Through the description of a clinical case that is part of a longitudinal study yet to be completed, the objective of this clinical study is to present an original technique for sinus elevation with crestal approach and simultaneous insertion of implants, called “Advanced Simplified Osteotome Technique” (ASOT) which improves the predictability of the implant therapy in alveolar crests with subsinus vertical dimensions ≤ 3 mm. (J Osteol Biomat 2012; 2:71-81)

Key words: Implant, Sinus elevation, Osteotome Technique, Sinus augmentation.

1 2

Private practice, Bologna, Piazza Aldrovandi 12, Italy Private practice, Medicina, Bologna, Via Saffi 20, Italy

Corresponding author: *Sforza, Nicola Marco, DDS, private practice, Bologna, Piazza Aldrovandi 12. tel: 051 222542, 051 7459053 - fax: 051 6568042 - mail: nsforza@studiosforza.net.

INTRODUCTION Positioning implants in the rear area of the upper jaw can often present difficulties due to low bone quantity. The reduction in height and thickness of the alveolar crest can be caused both by an increase in the size of the maxillary sinus (pneumatization), and by bone reabsorption resulting from extractions or outcomes of periodontal diseases. Under these circumstances, in order to correctly position a properly sized implant, a large number of techniques aimed at increasing bone quantity have been described: maxillary sinus floor augmentation, bone grafts, Guided Bone Regeneration (GBR), or a combination of these. In cases where pneumatization of the maxillary sinus can be observed, be it associated with a reabsorption of the alveolar crest or not, performing a maxillary sinus augmentation with lateral or crestal approach can be recommended. Maxillary sinus floor augmentation with lateral approach – sometimes known informally as “sinus lift” – is the most frequently applied technique. It was first described by Tatum1 and it is performed by accessing the sinus via a “window” placed on the lateral wall of the maxillary bone and by inserting graft material apically to the sinus floor. Long-term success of this proce-

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dure, along with its technical, implant and prosthetic aspects, are well documented in scientific literature2. In 1994, Summers introduced a less invasive approach to sinus floor augmentation, i.e. Osteotome Sinus Floor Elevation (OSFE) e Bone Added Osteotome Sinus Floor Elevation (BAOSFE). These techniques use a “transcrestal” approach to the maxillary sinus, employing manual instruments designed by the Author – Summers osteotomes – that compress the bone tissue of the implant site both laterally and apically. The first study was carried out on a population of 55 patients who presented alveolar crests with a residual height ranging from 5 to 10 mm. With 143 implants inserted, success rate equaled 96%3-4-5-6. Subsequently, other authors introduced a series of changes in Summers’ original technique, as far as implant surface, surgical protocol and the use of instruments such as video X-ray and sinuscopy are concerned. In particular, Bruschi et al. (1998), in a longitudinal study carried out on 303 patients and 499 implants, propounded the use of instruments different from Summers’ osteotomes for preparing the implant site, achieving a success rate of 97.5%, according to Albrektsson’s criteria7. Deporter et al. (2000) placed emphasis on the use of porous surfaces when placing implants in crests having a residual vertical dimension lower than 5 mm. 26 implants placed on 16 patients were 100% successful8; Cavicchia et al. (2001) conducted a study on 97 implants, obtaining a success rate of 88.6%, and they suggested that the fracture of the sinus

Journal of Osteology and Biomaterials

floor be performed without interposing graft material between osteotome and bone cortex9. The common aspect between Summers’ technique and the Authors who modified it, is the recommendation to perform the mini sinus lift in alveolar crests with residual dimensions ≥ 5 mm. In support of this thesis, Rosen et al. (1999) conducted a retrospective, multicenter study to assess the effectiveness of Summers’ procedure on 101 patients and 174 implants. Survival rate was 96% in alveolar crests with residual height ≥ 5 mm and 85.7% in crests with residual height < 5mm10. In 2008, in a longitudinal study on 26 patients and 39 implants, Sforza et al. modified Summers’ technique with a combined use of burs and osteotomes that reduces further the morbidity of the mini sinus lift technique with the crestal approach. This procedure, known as Simplified Osteotome Technique (SOT), allows to obtain high implant success rates (97%) on crests with residual height >= 5 mm11. These results have also been confirmed by Pjetursson et al. in a longitudinal study on 181 patients and 252 implants. In particular, survival rate was 91.3% in residual alveolar crests ≤ 4 mm, 90% in

residual alveolar crests ranging from 4 mm to 5 mm and 100% in residual alveolar crests > 5 mm12. These data show that the height of the residual crest is a crucial factor for the effectiveness of sinus elevation techniques with transcrestal approach, in that it influences its success rates. Through the description of a clinical case that is part of a longitudinal study yet to be completed, the objective of this clinical study is to present an original technique for sinus elevation with crestal approach and simultaneous insertion of implants, called “Advanced Simplified Osteotome Technique” (ASOT) which, combined with SOT, allows to improve the predictability of the implant therapy in alveolar crests with subsinus vertical dimensions ≤3 mm. CASE REPORT The patient (B.G., 67 years old, male) was sent to us by a colleague, to restore the upper-left sector by means of an implant prosthetic therapy. Overall, the patient was in good health, with no chronic systemic diseases, non-smoker. Five months prior to the dental examination, teeth number 24 and 27 were extracted. From a clinical point of view, there were no signs of active periodon-

Figures 1a, 1b. Clinical pictures of the edentulous crest, where a massive vertical and horizontal bone resorption can be seen clearly.


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Figures 2a. Intraoral X-ray of quadrant II: the residual sub- Figures 2b. CT scan image showing a superimposition of the implant sinus bone volume available for implant positioning is low. templates in position 24, 25 and 26. Bone quantity needs to be increased.

titis. Good level of oral hygiene, with Full Mouth Plaque Score (FMPS) and Full Mouth Bleeding Score (FMBS) < 15%. A maintenance therapy program with periodic sessions was scheduled. In quadrant II, a vertical and horizontal vestibular atrophy of the bone crest (Figures 1a, b). The patient had undergone a CT scan 2 months prior to the examination, in which a reduced quantity of sub-sinus residual bone (up to <3mm) could be observed. It had probably been caused by the reabsorption of the edentulous crest and by the pneumatization of the maxillary sinus. This was also confirmed by an intraoral

X-ray examination of quadrant II (Picture 2a). A template of the implant was applied onto the CT scan images in order to measure the quantity of residual bone: 9 mm in area 24; 5 mm in area 25 and 2 mm in area 26 (Picture 2b). Bone quality was assessed subjectively by the surgeon expert in implant therapy, upon surgery, while using the first surgical bur. Based on the clinical and radiographic observation and on the analysis of the case studies, the surgeon scheduled the placement of a 4x10mm implant in position 24 without sinus floor elevation, of a 4x10mm implant in position 25 applying the SOT

technique and of a 5x10mm implant in position 26 with the new ASOT procedure. Moreover, a procedure for increasing the horizontal volume of the vestibular bone crest in areas 24 and 25 was also scheduled. After signing the informed consent form, the patient was administered a non-steroidal anti-inflammatory drug (Aulin速, 100 mg; Roche, Milan, Italy) and an antibiotic (Amoxicillin EG速, 2 g) and a mild sedative (Valpinax速, 20 mg; Crinos) one hour before surgery. Lidocaine was used for local anesthesia (Ecocaine 速 20 mg, Molteni Dental; solution: 1:50000).

Figures 3a, 3b. Full-thickness flap elevation with releasing incisions.

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A linear, crestal incision was performed, with mesial releasing incisions on tooth 23, both vestibularly and lingually. A flap was elevated full-thickness above the mucogingival line, with complete esposition of the residual bone crest (Figures 3a, b). Preparation of the implant sites and implant positioning: - Residual bone quantity: 9 mm. Bone quality: type II/III13. The site was prepared using traditional dental burs: ball diameter 2, twist drill diameter 2, pilot

drill diameter 2/3, twist drill diameter 2.8; the site so prepared was not countersinked nor tapped. - Residual bone quantity: 5 mm. Bone quality: type IV13. The site was prepared using the SOT technique as described in literature11; the following stages were followed: a guide hole was drilled with a ball drill with diameter = 2 mm; preparation of the implant site using only Summersâ&#x20AC;&#x2122; osteotomes with increasingly larger diameters numbers 1, 2 and 3, which were rotated and pressed manually to reach the working

depth; preparation of the graft material, composed of bovine demineralized bone (BIO-OSSÂŽ); fracture of the sinus floor after having inserted and compacted a small amount of grafting material, by using the last osteotome used to prepare the implant site, on which the pressure of 2-3 light strokes of a surgical hammer was applied; sinus lift with subsequent increases of the grafting material and compaction using the osteotomes, which were inserted manually for 5 mm except for the last compaction procedure, which was

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Figures 4a, b, c, d. Site 25: performance of SOT technique. Figure 4a. Graphic illustration of the pre-implant site. Figure 4b. preparation of site 25 with manual instruments having increasing diameter no.1, 2 and 3 at 1 mm from sinus floor. Figure 4c. Positioning of graft material and sinus floor fracture by means of the last osteotome used for implant site preparation. Figure 4d. Sinus floor elevation by adding small amounts of graft materials and implant site preparation with manual instruments at a working length of 9 mm (1 mm less than the length of the implant to be positioned).

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Figures 5a, b. ASOT technique. Figures 5a. A guide hole was performed in position 26 by means of a ball drill with diameter = 2 mm. Figures 5b. Occlusal clinical photograph of site 26 after having performed and expanded the guide hole: the Schneiderian membrane is intact.

performed at a depth of 9 mm (1 mm less than the original implant length). At each stage, after the fracture of the sinus floor, the Valsalva maneuver was performed in order to verify, from a clinical point of view, that the Schneiderian membrane was not perforated (Figures 4a, b, c, d). - Residual vertical bone quantity: 2 mm. Bone quality: type IV13. The site was prepared using the new, modified SOT technique (ASOT) to approach residual bone crests with dimensions <= 3 mm: I. A guide hole was drilled with a ball drill with diameter = 2 mm to a depth of 1 mm from the sinus floor; II. Preparation of the implant site: the site was prepared using the same ball drill until the Schneiderian membrane was reached. The diameter was enlarged to 3 mm in order to allow access to the manual instruments (Figures 5a, b). III. Sinus membrane detachment: by means of an alveolar curette Lucas HFCL 84-E5, the membrane was detached for about 1 mm, in a circumferential direction in relation to

the access hole. This procedure was possible thanks to the low resistance of the membrane as a result of the sinus lift already performed on the mesial site with the SOT technique. Subsequently, collagen – accurately dimensioned, i.e. cut in small cubes with sides measuring 3 mm – was positioned and by means of the osteotomes, which were never pushed beyond the sinus floor, it was compacted toward the membrane in 5-6 times subsequently. IV. Sinus lift: small amounts of grafting material (demineralized bovine bone – Bioss®) were added 4-5 times subsequently and carefully compacted with osteotome no. 3, to reach a maximum depth of 5 mm. At the end of this procedure, the osteotome was pushed delicately to a depth of 9 mm (1 mm less than the original implant length) and the negativity of Valsalva’s sign was verified. V. Implant positioning: starting from the most mesial position, following a conventional procedure and without using any cooling fluid, the

cylindrical 4X10 implants 3i Biomet Nanotite were inserted in position 24 and 25, and the cylindrical 5X10 implant Nobelbiocare Tiunite MKIV was inserted in position 26, by means of a low-speed handpiece. At the end of the procedure, the following torque values were recorded: 50N for tooth 24, 50N for tooth 25 and 35N for tooth 26 (Figure 6a, b, c, d, e, f, g, h). It is important to notice that after these procedures the use of osteotomes has created not only a vertical augmentation of the bone quantity but an increase of the bucco-palatal dimension of the alveolar crest as well; that could be observed also from a clinical point of view. (see Figure 3b, 5b). As there was a minor vestibular dehiscence on tooth 24 and bone thickness measured < 2 mm in the site of tooth 25, the thickness of the peri-implant tissue was increased by adding demineralized bovine bone (Bioss®) covered by a connective tissue graft taken from the thickest palatine flap (Figure 7a, b, c, d).

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d Figures 6a, b, c, d, e, f, g, h. ASOT technique. Figures 6a, b, c. Clinical picture and illustration of the manual detachment of the Schneiderian membrane. Figures 6d, e. Manual insertion and compaction of collagen, aimed at protecting the sinus membrane. Figure 6f. Positioning and compaction of the graft material to obtain sinus floor elevation. Figure 6g. Completion of implant site preparation by means of osteotome no. 3, at a working length of 9 mm (1 mm less than the length of the implant to be positioned). Figure 6h. Illustration of the implants once positioned.

A PTFE monofilament (Gore-Tex®) 5/0 with inverted mattress and interrupted sutures was performed (Figure 8). At the end of the surgery, an intraoral Xray examination was carried out using the parallel technique in order to check that the sinus floor elevation had been successful (Figure 9). Drug treatment was prescribed with Aulin® (100 mg 12 hours after surgery) and with Amoxicilline EG® (1g/die for 7 days by mouth). Sutures were removed after 10 days. After 6 months, a new intraoral X-ray examination was performed. The implant head impression was taken for

Journal of Osteology and Biomaterials

the provision of provisional fixed prostheses to be screwed directly at the implant platform and kept for a threemonth period. When the final impression was taken and upon cementation (Figure 10a, b, c, d, e, f), another X-ray examination was taken, which confirmed that the bone levels obtained had been maintained. The patient was included in a customized maintenance therapy protocol with examinations to be held every 3 months and intraoral X-ray examinations at 6 months post cementation, after one year and every following year.

The implants are still in function and meet the Albrektsson’s criteria for success after a 3 years loading. (Figure 11a, b). DISCUSSION Transcrestal maxillary sinus floor elevation allows to place implants with subsequent implant-prosthetic rehabilitation. The procedure is particularly successful in cases in which massive atrophy is present in rear-upper jaws where the dimension of the residual bone crest is reduced due to a pneumatization of the maxillary sinus2-9,11. In


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a

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Figures 7a, b, c, d. Clinical pictures taken immediately after implant positioning. Dehiscence can be noticed in site 24, as well as a reduced residual thickness in site 25, which were offset by adding deproteinized bovine bone (BioOssÂŽ) and a connective tissue graft.

particular, scientific literature suggests that the success of the implant placement is strictly related to the vertical dimensions of the residual crest, taking 5 mm as a minimum reference height in order to obtain a high predictability rate10. In clinical reality, situations in which residual bone quantity is equal or lower than 5 mm are rather frequent. For this reason, to develop a mini-elevation technique is particularly interesting, in that it allows to solve complex cases without having to apply more invasive and dangerous methods such as the maxillary sinus floor elevation tech-

nique with lateral approach. Moreover, an important advantage of the transalveolar approach â&#x20AC;&#x201C; even in cases in which the dimensions of the bone crest are very low â&#x20AC;&#x201C; is that implants are placed simultaneously with the sinus floor elevation, thus ensuring a quick surgical technique with a low morbidity. In this particular clinical case, 3 implants were placed in position 24, 25 and 26, with a residual vertical bone crest measuring 10 mm, 5 mm and 2 mm, respectively. In all three sites, a high primary stability was achieved. As shown in literature for cases of maxil-

lary sinus floor elevation with lateral approach and simultaneous implant placement when the dimensions subsinus residual bone crest are very low14, this was possible thanks to the change introduced in the preparation of the implant site. In fact, this determines a sub-preparation of the site itself which, combined with the use of implants having a suitable macro- and micro-structure, allows to achieve high levels of implant stability. Furthermore, in this specific case of maxillary sinus floor elevation with transalveolar approach, the primary stability of the implants was achieved also thanks to a

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Figures 8. Clinical picture of the PTFE monofilament suture (GoreTex®) 5/0 with inverted mattress and interrupted sutures.

lateral and apical bone compaction by means of osteotomes. The management of Schneiderian membrane is a crucial factor for successful sinus floor elevation and minielevation procedures, in that it minimizes post-surgery complications. In a recent systematic review of scientific literature15, it was reported that in maxillary sinus floor elevation technique with transcrestal approach, the perforation of the membrane had an incidence ranging from 0% to 21.4%, resulting in post-surgery complications in 2.5% of the cases. The prognostic meaning of a perforation of the sinus membrane is still unclear; in fact, according to some Authors16, the integrity of the membrane does not appear to be crucial to retain the graft material and for the overall success of the technique, whereas according to other Authors17, a perforation of the Schneiderian membrane would be the cause of a reduced bone regeneration. To date, given the absence of reliable scientific evidence, the integrity of the membrane remains a primary objective

Journal of Osteology and Biomaterials

Figures 9. Post-surgery intraoral X-ray.

in the procedures for maxillary sinus floor elevation. In the clinical case presented here, a 5 mm sinus elevation in position 25 and a 8 mm sinus elevation in position 26 were obtained. If these elevations had been obtained with a transalveolar approach, the risk of lacerations would have been very high. In order to reduce said lacerations, the Authors suggest the membrane be detached progressively, thus minimizing the strains. In particular, site 25 – with a residual bone quantity of 5 mm – was treated first; the sinus floor elevation was obtained by subsequent additions of biomaterial on the one hand, and by delicately compacting the osteotomes – with increasing diameters – after having used burs, according to the transalveolar technique SOT11, on the other. First, the sinus floor elevation in the mesial site was obtained; in site 26, on the other hand, the membrane presented a low strain thanks to its progressive shift toward its mesial component, and an elevation that completed the one already performed in site 25 was obtained, according to the original technique described by the

Authors and referred to as ASOT. The type of graft material used to obtain the sinus floor elevation determines different biologic responses and healing courses. The use of autologous bone appears to represent the gold standard thanks to the osteoinductive properties that only this type of graft can guarantee2,13. However, in order to reduce the morbidity of the surgery and to avoid a second harvesting of graft material, other, highly successful sinus floor elevation techniques have been described in literature, which combine the use of autologous bone with alloplastic material, or even grafts performed with bone surrogate material only. In this regard, in a systematic review of scientific literature18, the Authors demonstrated that the implant survival rate after 3 years equaled 88.45% in autologous bone grafts, 90.95% in autologous bone grafts combined with other surrogates, and 95.25% in cases where only bone substitutes were used, such as demineralized bovine bone. Also from a volumetric point of view, bone surrogate graft materials appear


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Figures 10a, b, c, d. Clinical pictures and X-ray images taken upon final impression and upon cementation of the final prosthesis. Figures 10e, f. Comparison between the patientâ&#x20AC;&#x2122;s condition before surgery and after the cementation of the final prosthesis.

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Figures 12a,b. Clinical pictures and X-ray image taken at the three-years follow-up

to have a higher stability over time2. In this regard, the osteoconductive properties of the low-resorption bone surrogate graft material seem to ensure a higher clot stability, as well as to effectively function as a space maintainer. The risk of contraction of the sinus area expanded surgically â&#x20AC;&#x201C; which is generally caused by the compression suffered by the membrane at every respiratory act â&#x20AC;&#x201C; is therefore lower than in cases where only autologous bone graft or no graft at all are used. In this study, space is created and maintained thanks to the use of demineralized bovine bone in implant site 25, and to a collagen sponge conveniently fragmented and then combined with demineralized bovine bone in implant site 26, along with the support provided by the simultaneous positioning of the implants. The rationale for the use of the bone substitute was related to the long-term maintenance of a more stable sinus floor elevation volume obtained surgically, as compared to the volume stability that could be obtained by using a collagen sponge only.

Journal of Osteology and Biomaterials

CONCLUSION The positioning of implants in atrophic rear jaws can also be performed in clinical situations in which the height of the residual bone crest is equal to or lower than 3 mm. In particular, it is crucial to pay special attention to a number of surgical procedures aimed at increase primary stability, such as the sub-preparation of the implant site and the manual condensation by means of osteotomes. The management of the elevation of the Schneiderian membrane must be progressive, i.e. the membrane must be first detached in the area where the bone quantity is higher, then in the areas where atrophy can be observed, in order to minimize the risk of perforation. Therefore, when primary and tissue stability are adequate, the positioning of the implant is made possible thanks to the insertion of graft material and to the compaction with ostetomes. The ASOT technique offers an alternative approach to the lateral sinus floor elevation technique when massive atrophy of the maxilla is present. How-

ever, more longitudinal studies need to be carried out in order to verify its success rate and the long-term predictability of the results.


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REFERENCES 1. Tatum H. (1986) Maxillary and sinus implant reconstructions. Dent Clin North Am 30(2):207-229. 2. Jensen OT, Shulman LB, Block MS, Iacono VJ. Report of the Sinus Consensus Conference of 1996. Int J Oral Maxillofac Implants 1998;13 Suppl:11-45. Review. 3. Summers RB. A new concept in maxillary implant surgery: the osteotome technique. Compend Contin Educ Dent 1994;15:152-160. 4. Summers RB. The osteotome technique: Part 2 - The ridge expansion technique. Compend Contin Educ Dent 1994;15:422-436. 5. Summers RB: The osteotome technique: Part 3 – Less invasive methods of elevating the sinus floor. Compend Contin Educ Dent 1994;15:698-708. 6. Summers RB. The osteotome technique: Part 4 – Future site development. Compend Contin Educ Dent 1995;16:1090-1099. 7. Bruschi GB, Scipioni A, Calesini G, Bruschi E. Localized management of sinus floor with simultaneous implant placement: a clinical report. Int J Oral Maxillofac Implants 1998;13:219-226. 8. Deporter D, Todescan R, Caudry S. Simplifying management of the posterior maxilla using short, porous-surfaced dental implants and simulteneous indirect sinus elevation. Int J Periodontics Restorative Dent 2000;20:477-485. 9. Cavicchia F, Bravi F, Petrelli G. Localized augmentation of the maxillary sinus floor through a coronal approach for the placement of implants. Int J Periodontics Restorative Dent 2001;21:475-485. 10. Rosen PS, Summers R, Mellado JR et al. The bone-added osteotome sinus elevation technique: multicenter retrospective report of consecutively treated patients. Int J Oral Maxillofac Implants 1999;14:853-858.

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11. Sforza NM, Marzadori M, Zucchelli G. Simplified osteotome sinus augmentation technique with simultaneous implant placement: a clinical study. Int J Periodontics Restorative Dent. 2008;28(3):291-9. 12. Pjetursson BE, Ignjatovic D, Matuliene G, Brägger U, Schmidlin K, Lang NP. Transalveolar maxillary sinus floor elevation using osteotomes with or without grafting material. Part II: Radiographic tissue remodeling. Clin Oral Implants Res. 2009;20(7):677-83. 13. Lekholm U, Zarb GA. Patient selection and preparation. In Brånemark P-I, Zarb GA, Albrektsson T (eds). Chicago: Quintessence 1985:199-209. 14. Esposito M, Piattelli M, Pistilli R, Pellegrino G, Felice P. Sinus lift with guided bone regeneration or anorganic bovine bone: 1-year post-loading results of a pilot randomised clinical trial. Eur J Oral Implantol. 2010;3(4):297-305. 15. Tan WC, Lang NP, Zwahlen M, Pjetursson BE. A systematic review of the success of sinus floor elevation and survival of implants inserted in combination with sinus floor elevation. Part II: transalveolar technique. J Clin Periodontol. 2008;35(8 Suppl):241-54. 16. Jensen J, Sindet-Pedersen S, Oliver AJ. Varying treatment strategies for reconstruction of maxillary atrophy with implants: results in 98 patients. J Oral Maxillofac Surg. 1994;52(3):210-8. 17. Vlassis JM, Fugazzotto PA. A classification system for sinus membrane perforations during augmentation procedures with options for repair. J Periodontol. 1999;70(6):692-9. 18. Del Fabbro M, Rosano G, Taschieri S. Eur J Oral Sci. Implant survival rates after maxillary sinus augmentation. 2008 Dec;116(6):497-506.

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Original article

Vertical bone augmentation using bone cores from the mandibular symphysis area. Cases report Alexander Veis*, Dimitra Katzouraki, Irodis Barlas, Nickos Dabarakis.

Resorption of alveolar bone in the esthetic zone presents a challenge for the reconstructive dentistry. Inadequate bone volume for implant placement is usually observed following extraction of hopeless lower incisors due to periodontal, endodontal reasons or root cracks. In such cases vertical bone augmentation prior to implant placement should be considered. Although xenografts, alloplastic bone grafts, and allografts have been proposed for alveolar ridge augmentation, the use of a material with osteogenic and osseoinductive properties such as the autogenous bone still remains the gold standard for vertical bone augmentation procedures. This study presents two clinical cases that were treated using a staged approach i.e. vertical bone augmentation and secondly implant placement in lower incisor region, using onlay bone grafts harvested from the proximal mandibular symphysis area. Collagen membranes were placed to cover the block graft in an effort to reduce the potential graft resorption. The initial achieved vertical height was 7.2 mm (case 1) and 6.85 mm (case 2) during graft placement and the final vertical bone gain 12 months postrestoration was 4.6mm and 6.2mm respectively. Although there are no similar studies using the same technique for direct comparison of graft resorption, our findings are in accordance with previous studies where block type autografts were used for vertical augmentation. (J Osteol Biomat 2012; 2:83-89)

Key Words: vertical bone augmentation, autogenous bone grafts, block type grafts.

Department of Surgical Implantology & Roentgenology, Aristotle University of Thessaloniki, Greece Correspondence to: * Veis Alexander, 5 Theochari Str., 54621 Thessaloniki, Greece tel. +302310269079, fax +302310269079, e-mail: aveis@dent.auth.gr

INTRODUCTION Resorption of alveolar bone in the esthetic zone presents a challenge for the reconstructive dentistry. It may compromise implant placement and jeopardize the aesthetic outcome. Both vertical bone augmentation and soft tissues enhancement at the defected site are usually necessary. A variety of different techniques with the word utilize membranes and particulate bone grafts, distraction osteogenesis, and bone block grafting either alone or in combination with a membrane.1 Immediate post-extraction implant placement compromise implant stability and esthetic outcome. The possibility of the implantâ&#x20AC;&#x2122;s threads exposure following GBR techniques in conjunction with immediate implant placement was higher due to marginal bone/graft resorption and/or complications such as membrane exposure, during healing.2 A staged approach is usually the therapy of choice in patients lacking adequate bone volume. Inadequate bone volume in lost or lower incisor region presents a site where the defect is confined by remaining bone partially or not at all. Vertical bone augmentation prior to implant placement should be considered. Although xenografts, alloplastic bone

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grafts, and allografts have been proposed for alveolar ridge augmentation, the use of a material with osteogenic and osseoinductive properties such as the autogenous bone still remains the gold standard for vertical bone augmentation procedures in such cases. The proximity of the defected area dictates the mandibular symphysis region to serve as donor site. This choice reduces patientâ&#x20AC;&#x2122;s morbidity since the whole surgery negotiates with one surgical site. The quality of the graft has been documented in several studies indicating that intraorally harvested intramembraneous bone grafts from the mandibular symphysis demonstrate less resorption, enhanced revascularization and better incorporation at the recipient site as compared with the extraorally harvested endochondral bone grafts.3 The purpose of this study was to present two clinical cases of vertical bone augmentation in lower incisor region, using bone cores harvested from the proximal mandibular symphysis area and used as onlay bone grafts. Dental implants were placed following the maturation of the grafted area. Case 1 A 38 years old woman exhibited bone loss due to root resorption and subsequent inflammation around the endodontic post of tooth # 31. Medical history was clean without any limitation for bone regeneration and/or implant osseointegration procedures. The therapy plan included extraction of the hopeless tooth, autologous bone grafting and in second stage implant placement. Following local anesthesia a midcrestal incision was designed

Journal of Osteology and Biomaterials

continuing into the gingival sulcus. A full thickness flap was elevated with vertical vestibular releasing incisions distally of the proximal incisors that were advanced up to 10 mm beyond the apexes (Figure 1). After exposure of the mandibular frontal ridge, a 5mm trephine burr was aligned 5 mm below the apexes of the proximal incisors vertically to vestibular bone. Using copious irrigation the trephine was rotated with 600 rpm, inserted 10mm in depth (Figure 2) and removed leaving a round osteotomy confining the margins the bone core. The bone core was then carefully released, removed from the donor site and a hole was created axially in the centre of the core using a lag bur to allow a free passing for the retention screw (Figure 3). Additional particulate bone chips were harvested from the bottom of the donor site and kept together with the bone core in a sterile metallic dispenser. The recipient site was carefully adjusted through flattening of its bottom and the bone core was fixed firmly in place using a 1.2 mm in diameter and 10 mm in length fixation screw (Figure 4). A collagen resorbable membrane (Osseoquest Biomet 3i, Palm Beach Gardens, FL) was then placed beneath the reflected lingual flap and any dehiscence around the fixed bone core was filled with the particulate autologous bone graft (Figure 5). The osteotomy at the donor site was filled with surgical wax in order to control bleeding and enhance healing. The augmented area plus 3-4 mm of healthy surrounding bone were covered by the membrane. Periosteal releasing incisions were made to allow a tensionâ&#x20AC;&#x201C;free closure of the flaps over the membrane using a combination of

Figures 1. Initial radiographic view (taken from the panoramic x-ray) of the hopeless lower incisor #31and the remaining osseous defect after extraction of the tooth.

Figures. 2. It is shown the use of a 5mm trephine bur to cut and retrieve a bone core from the mandibular symphysis area.

mattress and interrupted sutures with Prolene (Johnson & Johnson) (Figure 6). Antibiotics (Amoxicilin 500 mg, Glaxo Smithkline AEBE) was prescribed for the following 8 days. Nimesulide 100 mg twice daily, were used for pain control (Boehringer Ingelheim AE). The patient was instructed to use 0.2 % chlorhexidine mouthwash twice daily for the first 3 weeks and ice packs were suggested to be used for 5h after surgery. The healing of the surgical area was uneventful and the sutures were removed 8 days after surgery. The patient was scheduled for recall visits


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Figure 3. Retrieved bone core together with particulate bone taken from the donor site

Figure 4. The bone core was stabilized in place at the base of the osseous defect.

every 3 weeks after suture removal to ensure adequate tissue healing. Graft incorporation, maturation and relative resorption can be seen in periapical digital x-rays in Figures. 7a (graft placement), and 7b after 6 months from surgery when the patient was scheduled for implant placement. Vertical bone height and relative graft resorption were measured according to a reference length of the retention screw. After six months of graft healing the vertical graft resorption was 2.2 mm (7.2 mm-5 mm, Figures. 7a and 7b). Due to 2.2 mm of resorption the head of the retention screw was protruding beneath the mucosa (Figure 8). The patient received the same as previously medication and the surgical site was reopened by means of a crestal and two vertical releasing incisions at the proximal natural incisors (Figure 9) and the retention screw was removed (Figure 10). An oclussal view of the surgical area can be seen in Figure 11 where a relative resorption in a bucco-lingual direction was obvious

after meticulous removal of soft tissues remnants leaving a 4 mm width of healthy augmented new bone. Following debridement, a 3.25 to 13 mm screw type dental implant (micro-mini Biomed 3i, Palm Beach Gardens, FL) was installed (Figure 12) with a 3 mm healing abutment in place according to a single phase surgical protocol. A digital periapical x-ray was taken after implant placement where the remaining 5mm of graft height can be seen in Figure 13. The restoration took place after 4 months of healing period. After 12 months post-restoration a clinical photo (Figure 14) and an x-ray were taken. The implant was used as a reference length to measure the final graft restoration. 0.4 mm of graft resorption was measured from the time of implant installation (remaining graft height=4.6 mm, Figure 15). The total vertical resorption from the graft placement was 2.6mm (7.2mm-4.6mm=2.6mm).

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Figure 5. Particulate autogenous bone graft was used to fill ant empty space around the bone core.

Case 2 A 28 years old woman with clean medical history came to our office complaining for swelling at the buccal area in front of tooth #31. The x-ray revealed extensive resorption around tooth #31, (Figure 16), and according to the dental history the resorption was due to traumatic pulp necrosis resulting to an endo-perio lesion. The tooth was extracted immediately, the extraction socket was cleaned and left for healing according to first intention for 6 weeks. Following the post-extraction healing period, vertical bone augmentation at the defected site was performed a bone core taken from the proximal chin area and as described in the previous case. The bone core was fixed at the bottom of the defect by means of a retention screw and all the empty spaces were filled with autologous particulate bone as it seems in the x-ray (Figure 17), immediately after installation. As in the previous case a collagen resorbable membrane (Osseoquest Biomet 3i, Palm Beach Gardens, FL) was used

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Figure 6. A collagen membrane was used to cover the augmentation material and subsequent suture of the tension free flap.

Figures 7a.,7b. Periapical digital x-rays show the graft during placement (7,2mm in height) and after six months of healing (5mm in height).

Figures 9, 10, 11. Clinical view of the augmented area after flap reflection, removal of the retention screw and coronal view of the augmented area.

Journal of Osteology and Biomaterials

to cover the augumented area. The maturation of the graft can be seen in radiographs (Fugures 18 and 19) after 3 and 6 months respectively and the vertical graft resorption was measured 0.35mm (6.85mm-6.5mm). During implant placement surgery, the graft retention screw was removed (Figure 20) and as in previous case an implant (3.25 to 13 mm screw type micro-mini implant Biomed 3i) was placed according to a single phase protocol. Figure 21a and 21b show the x-rays of the implant at the installation day and 12 months

Figure 8. Clinical view of the augmented area after six months. The head of the retention screw is protruding beneath the mucosa.


Veis A et al.

Figures 12, 13. Implant placement following a one phase protocol and a post-installation periapical x-ray.

after the restoration revealing a vertical bone resorption 0.3mm (6.5mm6.2mm). The total graft resorption from the time of graft placement up to the 12 months post-restoration recall was 0.65mm (6.85 mm-6.2 mm).

Figures 14,15. Clinical and radiographic views 12 months post-restoration. A total 4.6mm vertical augmentation outcome can be seen in fig. 21.

Discussion Prosthetic rehabilitation with dental implants in aesthetic area in field of severe osseous defects is still a challenge in implant dentistry. In such cases technique sensitive bone augmenta-

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tion procedures in horizontal and vertical directions are routinely needed and the treatment philosophy should include a two stage surgery i.e. first the lost bone reconstruction and in a second stage the implant placement.4 Especially for the rehabilitation in the lower incisors area there are certain local parameters that may compromise the overall result. The inherent buccolingual thin ridge results in fast bone resorption following periodontal tooth extraction and lack of lingual and/or buccal cortical plates.5 Such defects are not sufficiently confined by bone except and the osteogenetic sources at the recipient site are the bottom of the defect and perhaps any remaining bony walls around the mesial and distal proximal teeth. Moreover, the biotype of the mucosa at the lower incisor region is usually thin and scalloped leading to the need of complicate flap managment including mobilization and/or enhancement using connective soft tissue grafts.6 Dehiscenses and mem-

Figure 16. Extensive bone resorption can be seen in the initial x-ray around the incisor #31.

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Figures 17,18,19. X-rays during graft placement and 3 and 6months of healing. The initial vertical bone gain was 6.85mm reduced to 6.5mm after 6 months of healing.

Figures 20. Clinical views of the retention screw removal and the implant installation after 6 months of graft healing.

brane/graft exposure present usual complications during vertical bone grafting procedures.7 In the previous cases collagen membranes were placed to cover the block graft in an effort to reduce the potential graft resorption. The initial vertical height was 7.2 mm (case 1) and

graft resorption, our findings are in accordance with previous studies where block type autografts were used for vertical augmentation. Cordaro et al8 found a height reduction from 3.2 mm to 2.1 mm (i.e. 34%) when chin grafts were placed in maxilla. Less resorption was found by Proussaefs et al.9 (from 6.12 mm to 5.12 mm, 16.3%) using ramus grafts. Similarly, Chiapasco et al.10, published mean 0.6 mm resorption of ramus graft before implant placement being in agreement with the vertical graft resorption found in case 2. The final vertical bone gain was different in the presented cases due to higher resorption rate found in case 1. It should be mentioned that the major amount of resorption was calculated during graft healing period (2.2mm) while it was significantly lower from implant installation up to 12 months post-restoration (0.4mm). Although the technique that was used in both cases was quite similar followed by uneventful healing, variations in topography of the recipient site, the biotype of the mucosa and/or the patientâ&#x20AC;&#x2122;s care

6.85 mm (case 2) during graft placement and the final vertical bone gain was 4.6 mm and 6.2 mm during the 12 months recall respectively. The relative vertical resorption was 2.6mm and 0.6mm respectively. Although there are no similar studies using the same technique for direct comparison of

Figure 21a, 21b. X-rays during implant installation and up to12 months post-restoration. The total vertical bone gain was 6.2mm as it seems in fig. 27b.

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may influence the overall regeneration outcome. Moreover, the implants achieved successful endosseous integration since as it was stated the failure rates are comparable to those observed in native bone.5 Conclussions Vertical bone augmentation in lower incisors region, although presents a technique sensitive procedure, can be successful when a staged approach is used. Autogenous bone cores harvested from the proximal mandibular symphysis area present an excellent bone graft that provides osteogenic and osteoinductive capabilities. Resorbable membranes can be used to minimize the potential graft resorption. Dental implants can be successfully placed in a second stage following the graft maturation.

Acknowledgements The authors declare that they have no financial relationship with any commercial firm that may pose a conflict of interest for this study.

REFERENCES 1. McAllister  BS,  Haghighat  K. Bone augmentation techniques. J Periodontol 2007;78(3):377-96. 2. Becker W, Dahlin C, Becker BE, Lekholm U, van Steenberghe D, Higuchi K, Kultje C. The use of e-PTFE barrier membranes for bone promotion around titanium implants placed into extraction sockets: a prospective multicenter study. Int J Oral Maxillofac Implants 1994;9(1):31-40.

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10. Chiapasco M, Zaniboni M, Rimondini L. Autogenous onlay bone grafts vs. alveolar distraction osteogenesis for the correction of vertically deficient edentulous ridges: a 2-4-year prospective study on humans. Clin Oral Implants Res 2007;18(4):432-40.

3. Proussaefs P,  Lozada J. The use of intraorally harvested autogenous block grafts for vertical alveolar ridge augmentation: a human study.Int J Periodontics Restorative Dent 2005;25(4):351-63. 4. Artzi  Z, Nemcovsky CE, Tal H, Weinberg E, Weinreb M, Prasad H, Rohrer MD, Kozlovsky A. Simultaneous versus two-stage implant placement and guided bone regeneration in the canine: histomorphometry at 8 and 16 months. J Clin Periodontol 2010;37(11):1029-38. 5. Bernstein S, Cooke J, Fotek P, Wang HL. Vertical bone augmentation: where are we now? Impant Dent 2006;15(3):219-28. 6. Cosyn  J, De Bruyn H, Cleymaet R. Soft Tissue Preservation and Pink Aesthetics around Single Immediate Implant Restorations: A 1-Year Prospective Study. Clin Implant Dent Relat Res 2012 [Epub ahead of print] 7. Triaca  A, Minoretti R, Merli M, Merz B. Periosteoplasty for soft tissue closure and augmentation in preprosthetic surgery: a surgical report. Int J Oral Maxillofac Implants 2001;16(6):851-6. 8. Cordaro  L,  Torsello F,  Accorsi Ribeiro C,  Liberatore M,  Mirisola di Torresanto V. Inlay-onlay grafting for three-dimensional reconstruction of the posterior atrophic maxilla with mandibular bone. Int J Oral Maxillofac Surg  2010;39(4):350-7. 9. Proussaefs  P, Lozada J, Kleinman A, Rohrer MD.The use of ramus autogenous block grafts for vertical alveolar ridge augmentation and implant placement: a pilot study. Int J Oral Maxillofac Implants 2002;17(2):238-48.

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Journal of Osteology and Biomaterials

BioCRA

Jaswinder K. and Singh Z.


Original article

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A simplified technique for horizontal ridge augmentation: a case report with histological and histomorphometric analysis Marco Redemagni1, Giuliano Garlini1*, Giovanna Orsini2, Francesca Rossini3

The aim of this study was to investigate the clinical and histologic results of a case treated with a simple technique for horizontal ridge augmentation using deproteinized bovine bone without any membrane. In January 2008 we treated a patient who presented a severe horizontal mandible atrophy, with a simplyfied technique for horizontal augmentation and delayed insertion of 2 implants. After the healing period (8 months), all the implants appeared clinically- and radiologically-integrated. Twenty-one months after the DBBM grafting, with the patientâ&#x20AC;&#x2122;s consent, the implants were opened and an explorative surgical flap was performed to evaluate the quality and quantity of regenerated bone. At the same time two samples of bone were taken, with a trephine bur of 3mm diameter for histological analysis. The histological samples revealed new bone formation, which was compact, well organized with a lamellar structure. This simplified technique for horizontal ridge augmentation seems to be an encouraging method of obtaining bone augmentation in compromised patients, avoiding the use of resorbable or non-resorbable membranes. (J Osteol Biomat 2012; 2:91-97)

Key Words:horizontal augmentation, bone graft, implants.

Private practice in Milan and Lomazzo (Como), Italy Researcher, University of Ancona, Italy 3 Private practice in Monguzzo (Como), Italy 1 2

Correspondence to: * Prof. Giuliano Garlini Milan and Lomazzo (Como), Italy Email: giuliano@studiochierichettigarlini.it

INTRODUCTION The success of dental implants to support fixed or removable prostheses has been well-documented in the dental literature for 40 years1. The use of osseointegrated implants can provide predictable results in the presence of certain conditions, such as a residual alveolar bone width of at least 6 mm, an alveolar bone height of 10 mm, appropiate intermaxillary relationships, and peri-implant tissue of good quality with an adequate amount of keratinazed mucosa2. In order to achieve success in implant dentistry it is of fundamental importance the bone quality and quantity of the residual alveolar ridge. Unfortunately, sometimes there is a lack of bone width or height in the implant site, due to teeth loosening from periodontal disease, dentoalveolar trauma or endodontic lesions. In those situations, it is impossible to insert the implants with a prostheticdriven method. Some authors have suggested several contemporary treatment modalities to recreate an ideal bone environment, including autogenous onlay bone grafts, distraction osteogenesis, and guided bone regeneration (GBR)3. Although viable, each of these procedures presents potential complica-

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tions, and has shown limited success when addressing severe alveolar bone loss. Although autogenous bone is unequivocally accepted as the gold standard for bone reconstruction4, alternative bone grafting materials have been suggested. The reason most frequently cited for using a bone substitute is to overcome the shortcomings of autograft harvesting: intraoral donor sites are usually not sufficient to collect a large quantity of bone, and extra-oral donor sites are usually associated with high morbidity, hospitalization, and lengthy therapy. Among the bone substitute biomaterials, the deproteinized bovine bone mineral (DBBM) (Bio-Oss, Geistlich AG, Wolhusen, Switzerland) is widely used in implant dentistry5,6,7,8,9,10 and periodontology11,12,13. Several experimental animal studies14-15-16-17 indicate that DBBM may be incorporated into the bone tissue and that intimate contact will be established between the biomaterial and newly formed lamellar bone. Berglundh and Lindhe18 demonstrated in an animal experiment that Bio-Oss particles placed in a large self-contained defect became surrounded by newly formed bone; the authors thus concluded that the biomaterial acted as a scaffold for new bone formation. Similar findings regarding the osteoconductive properties of Bio-Oss were reported by Hämmerle and Karring,19 Araújo et al.20 and Carmagnola et al21-22 from studies in humans and dogs. GBR is used for ridge augmentation prior to or in conjunction with osseointegrated implant placement, whether with a barrier membrane alone or in

Figure 1. The initial clinical situation showing the reduced width of the residual alveolar process.

combination with bone grafts or bone substitutes. GBR offers predictability in providing bone augmentation simultaneously in both horizontal and vertical directions23-24, however, it is technically complex, with the possibility of a premature membrane exposure resulting in bacterial contamination25. To overcome this problems, research-

ers and clinicians strive to develop less invasive surgical modalities that are technically less demanding and promote faster bone regeneration. Thus, a technique that would eliminate the need for a barrier membrane and/or autogenous bone graft could be beneficial in reducing the incidence of complications and increasing the patientâ&#x20AC;&#x2122;s

Figure 2. Perforation of the cortical bone to promote vascularization of the bone graft

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Figure 3. The DBBM positioned to compensate for horizontal atrophy of the alveolar process

acceptance of the procedure26. The main purpose of this study is to present the clinical and histologic results of a simple technique for horizontal ridge augmentation with deproteinized bovine bone (Bio-oss, Geistlich AG, Wolhusen, Switzerland) and without any membrane (resorbable and unresorbable) avoiding the risk of exposure.

Clinical Case In January 2008 we treated a patient with the simplified technique for horizontal augmentation (STHA) with Deproteinized Bovine Bone Mineral (DBBM). The patient was a male of 44 years. He was suffering from an extreme bone atrophy on the left side

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of the mandible, and a regenerative procedure was necessary to augment horizontally the alveolar ridge in order to allow the implants insertion. One hour before surgery, general therapy was administered as follows: amoxicillin and clavulanic acid (Augmentin®, 1g /12 h for 6 days; Pharmacia, Milan, Italy), 30 minutes before surgery, each patient received diazepam (Valium®, 1 drop / 2 kg weight; Roche). Local anaesthesia was given with 2% ecocain (1:50000 epinephrine; Molteni Dental, Milan, Italy), and just before starting the patient rinsed his mouth with clorhexidine 0,2% for one minute. A midcrest incision was made distally from the last tooth to the retromolar area, without any vertical incision, to elevate a full-thickness buccal and lingual mucoperiosteal flaps. After the flap elevation, the bone crest was cleaned with a great attention in order to eliminate any residual connective tissue (figure 1). Cortical bone perforations were made with a round carbide bur, exposing the underlying medullary space, in order to increase the vascularization of the bone graft (figure 2). The DMBB was hydrated with a saline solution and placed beside the bone crest to compensate the horizontal bone defect (figure 3). With this technique the periostium remains intact and thus it is able to maintain a sort of “tent effect”, avoiding any infiltration of the heterologous bone chips from the connective tissue. To augment the mobilization of the flap some periosteal releasing incisions were made deeper, especially lingually, over the mylohyoid line, to obtain a primary tension-free wound closure.

Figure 4. The passive adaptation of the flap was completed with single sutures.

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Results The surgical site healed uneventfully during the 8 months following the correction of the mandibular defect. Surgical re-entry for the implant insertions, revealed the presence of bonelike tissue, a well defined crest, wide enough to receive implants.

Figure 5. At re-entry we observed good horizontal bone augmentation which will allow insertion of the implants

The passive adaptation of the flap was completed with single sutures in polyamid 5-0 (Surgipro- Syneture, USA)(figure 4). A local infiltration of corticosteroid (Soldesam forte, Lab.Farmacologico Milanese Srl, Caronno Pertusella, Varese, Italy) was made at the end of the

surgery, and nimesulid (AulinÂŽ, 50mg /12 h for 3 days; Roche, Verona, Italy) was given. The healing period lasted 8 months, after that period 2 implants were inserted (2 Xive Dentsply, Friadent, Mannheim, Germany) (figures 5,6).

Figure 6. Two implants inserted into the augmented bone

Journal of Osteology and Biomaterials

Processing of the samples 21 months after the DBBM grafting, with the patient consent, and respecting the ethical principles of the Declaration of Helsinki for research involving human subjects, an explorative surgical flap was performed to control the quality and the quantity of the regenerated bone. At the same time, two samples of bone were taken with a trephine bur of 3 mm of diameter, to be histologically analyzed. The histologic samples were fixed with formaline 10% and included in LR White resin (London Resin, Berkshire, U.K.). Histologic sections of 20-30Âľm width were obtained from the resin blocks with the aid of an abrasion and cutting system (Remet, Casalecchio di Reno, BO). The histologic samples were coloured with Toluidine blu and acid fucsin and observed with an optical microscope (Laborlux Microscope, Leitz, Wetzlar, Germany). Histologic observations The histologic samples revealed new bone formation, which was compact, well organized with a lamellar structure. Some osteocyte lacuna were present, together with some osteons. A regenerated zone was possible to observe at the periphery of the osteon, with new bone formation composed of immature bone tissue which are in-


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Figure 7. Light micrograph of the retrieved specimen: newly formed bone (NB) with lamellar features and large marrow spaces (MS) are evident. There are remnants of the bovine bone graft (G) in close contact with highly fuchsin-stained osseous tissue (*). Cement lines are present between the compact preexisting bone (PB) and the newly formed bone (arrows). Acid fuchsin and toluidine blue staining; original magnification: 10´.

Figure 8. Light micrograph showing a region of extremely compact bone composed of preexisting bone (PB) and areas of newly formed bone (NB), strongly stained by acid fuchsin. The different bone appositions are characterized by the presence of cement lines (arrows). The NB shows concentric lamellae organized around vascular structures that show neo-angiogenesis (*). Acid fuchsin and toluidine blue staining; original magnification: 10´

Figure 9. Light micrograph at high magnification showing newly formed osteons (Ost), composed of concentric lamellae with numerous osteocytic lacunae (white arrowheads). The osteons are delimited from preexistent bone (PB) by cement lines (arrows). Acid fuchsin and toluidine blue staining; original magnification: 20´

tensely coloured with acid fucsin. Some medullar spaces were present with an intense angiogenic process and surrounded by osteoid tissue. The Bio-Oss granules were well integrated with the new bone without any inflammatory or foreign body reaction (figures 7-8-9).

it is demanding, and frequently not accepted by the patients27. The guided bone regneration (GBR) is a very well documented technique, with excellent results when correctly utilized, but it is still demanding, very complex, operator dependent, with possible site infections for premature exposure of the membrane23. An alternative approach for the horizontal ridge augmentation could be the split-crest technique, that in some cases eliminate the need of a second stage surgery. However, it is technically complex, with possible accidental separation of the bone wall and its consequent osteonecrosis28. To overcome these problems, researchers and clinicians strive to develop less invasive surgical modalities that are technically less demanding and promote faster bone regeneration. Thus, a technique that would eliminate the need for a barrier membrane and/or

autogenous bone grafts could be beneficial in reducing the incidence of complications and increasing the patients’ acceptance of the procedure. We call this method simplify technique for horizontal ridge augmentation (STHA) . We applied this technique with the intention of using a regenerative technique without resorbable or nonresorbable membranes, in patients with a reduced mouth opening, poor compliance and collaboration. Avoiding the use of the barrier membrane it is possible to reduce the risk of an unintentional exposure of the membrane itself and consequent contamination of the bone graft. Concerning the healing and the bone regeneration we applied the same principles of the GBR: it is the periosteum that works as a membrane creating a “tent effect”, with the DBBM acting as a scaffold. The graft stabilize the clot, causing the differentiation of the marrow and mesenchimal cells in

Discussion Lack of sufficient bone in the alveolar process precludes implant placement. For this reason in some cases it is necessary to augment the bone horizontally or vertically prior to implant insertion. Even if autogenous bone is considered the gold standard for reconstructive materials in bone augmentation, because of the osteoproliferative, osteoinductive, and osteoconductive properties, not all the patients are suitable for more complex surgeries, including intra- and extra-oral bone harvesting. Distraction osteogenesis could be an alternative technique, but

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bone precursors cells. For these reasons, it is necessary to maintain the vestibular periostium intact, with the releasing incisions preferably only on the lingual flap to permit a complete tension free closure of the wound. Finally, to underline the effectiveness of the periostiumâ&#x20AC;&#x2122;s tent effect, other studies continue to highlight the importance of the periosteum as a source of progenitor cells during bone regeneration procedures29. The DBBM, for its slow resorption, is stable in time and is able to create a good bone volume in the augmented areas avoiding second surgery for autologous bone collection with a reduced morbidity for the patient.

Conclusions The simplified technique for horizontal ridge augmentation (STHA) seems to be an encouraging method to obtain a bone augmentation in compromised patients, avoiding the use of resorbable or non-resorbable membranes. The use of DBBM also eliminates the need to harvest autogenous bone from another site and reduces morbidity and discomfort to the patient. The authors present the results from a clinical case, which seems to be interesting and encouraging, and the technique is absolutely simple, predictable and of fast execution. This paper produces clinical evidence, supported by some histological analysis, confirming that the DBBM alone used without a barrier is able to horizontally augment the alveolar crest, otherwise insufficient for a prosthetic-driven implant insertion. These results must be confirmed obviously by other animal and clinical studies that investigate the unconventional use of DBBM for horizontal bone augmentation.

REFERENCES 1. Branemark PI, Zarb GA, Albrektsson T. Tissue integrated prostheses: Osseointegration in clinical dentistry. Chicago Quintessence 1985:211-232 2. Albrektsson T, Dahl E, Engenvall S, Enquist B, et al. Osseontegrated oral implants. A swedish multi center study of 8139 consecutively inserted Nobelpharma implants. Journal of Periodontology 1988; 5:287-296 3. Simion M, Rocchietta I, Kim D et al. Vertical ridge augmentation by means of deproteinized bovine bone block and recombinant human platelet-derived growth factor-BB: a histologic study in a dog model. Int J Period Rest Dent 2006;26:415-423 4. Cushing M. Autogenous red marrow grafts: Their potential for induction of osteogene- sis. J Periodontol 1969;40:492-497 5. Hämmerle CH, Lang NP. Single-stage surgery combining transmucosal implant placement with guided bone regeneration and bioresorbable materials. Clin Oral Implants Res 2001;12:9-18. 6. Piattelli M, Favero GA, Scarano A, Orsini G, Piattelli A. Bone reactions to anorganic bovine bone (Bio-Oss) used in sinus augmentation procedures: A histologic longterm report of 20 cases in humans. Int J Oral Maxillofac Implants 1999;14:835-840. 7. Valentini P, Abensur D. Maxillary sinus floor elevation for implant placement with dem- ineralized freeze-dried bone and bovine bone (Bio-Oss): A clinical study of 20 patients. Int J Periodontics Restorative Dent 1997;17:232-241. 8. Valentini P, Abensur D, Wenz B, Peetz M, Schenk R. Sinus grafting with porous bone mineral (Bio-Oss) for implant placement: A 5-year study on 15 patients. Int J Peri- odontics Restorative Dent 2000;20: 245-253. 9. Zitzmann NU, Naef R, Schärer P. Resorbable versus nonresorbable membranes in com- bination with Bio-Oss for guided bone regeneration. Int J Oral Maxillofac Implants 1997;12:844-852.

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10. Zitzmann NU, Schärer P, Marinello CP, Schüpbach P, Berglundh T. Alveolar ridge augmentation with Bio-Oss: A histologic study in humans. Int J Periodontics Restorative Dent 2001;21:288-295.

20. Araújo MG, Carmagnola D, Berglundh T, Thilander B, Lindhe J. Orthodontic move- ment in bone defects augmented with Bio- Oss. An experimental study in dogs. J Clin Periodontol 2001;28:73-80

11. Camelo M, Nevins ML, Schenk RK, et al. Clinical, radiographic, and histologic evalu- ation of human periodontal defects treated with Bio-Oss and Bio-Gide. Int J Perio- dontics Restorative Dent 1998;18:321-331.

21. Carmagnola D, Berglundh T, Lindhe J. The effect of a fibrin glue on the integration of Bio-Oss with bone tissue. A experimental study in Labrador dogs. J Clin Periodontol 2002;29:377-383.

12. Camelo M, Nevins ML, Lynch SE, Schenk RK, Simion M, Nevins M. Periodontal regen- eration with an autogenous bone-Bio-Oss composite graft and a BioGide membrane. Int J Periodontics Restorative Dent 2001;21: 109-119. 13. Mellonig JT. Human histologic evaluation of a bovine-derived bone xenograft in the treatment of periodontal osseous defects. Int J Periodontics Restorative Dent 2000; 20:19-29. 14. Berglundh T, Lindhe J. Healing around implants placed in bone defects treated with Bio-Oss. An experimental study in the dog. Clin Oral Implants Res 1997;8:117-124. 15. Araújo MG, Carmagnola D, Berglundh T, Thilander B, Lindhe J. Orthodontic move- ment in bone defects augmented with Bio- Oss. An experimental study in dogs. J Clin Periodontol 2001;28:73-80. 16. Carmagnola D, Berglundh T, Lindhe J. The effect of a fibrin glue on the integration of Bio-Oss with bone tissue. A experimental study in Labrador dogs. J Clin Periodontol 2002;29:377-383. 17. Carmagnola D, Adriaens P, Berglundh T. Healing of human extraction sockets filled with Bio-Oss. Clin Oral Implants Res 2003; 14:137-143. 18. Berglundh T, Lindhe J. Healing around implants placed in bone defects treated with Bio-Oss. An experimental study in the dog. Clin Oral Implants Res 1997;8:117-124. 19. Hämmerle CH, Karring T. Guided bone regeneration at oral implant sites. Periodontol 2000 1998;17:151-175.

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29. Simion M, Nevins M, Rocchietta I, Fontana F, et al. Vertical Ridge Augmentation Using an Equine Block Infused with Recombinant Human Platelet-Derived Growth Factor-BB: A Histologic Study in a Canine Model Int J Periodontics Restorative Dent 2009;29:245-255

22. Carmagnola D, Adriaens P, Berglundh T. Healing of human extraction sockets filled with Bio-Oss. Clin Oral Implants Res 2003; 14:137-143 23. Simion M, Trisi P, Piattelli A. Vertical ridge augmentation using a membrane technique associated with osseointegrated implants.” Int J Period Rest Dent 1994;14:496-511 24. Nevins M, Mellonig JT Enhancement of the damaged edentolous ridge to receive dental implants: a combination of allograft and the Goretx membrane. Int J Period Rest Dent 1992;12:97-111 25. Simion M, Trisi P, Maglione M, Piattelli A A preliminary report on a method for study the permeability of expanded polytetrafluoroetylene membrane to bacteria in vitro: a scanning electron microscopic and histological study. J Periodontol 1994;65:755-761 26. Simion M, Rocchietta I, Kim D et Al. Vertical ridge augmentation by means of deproteinized bovine bone block and recombinant human platelet-derived growth factor-BB: a histologic study in a dog model. Int J Period Rest Dent 2006;26:415-423 27. Froum SJ, Rosenberg ES, Elian N, Tarnow D, Cho SC. Distraction osteogenesis for ridge augmentation: Prevention and treat- ment of complications. Thirty case reports. Int J Periodontics Restorative Dent 2008; 28:337-345. 28. Scipioni A, Bruschi GB, Calesini G. The edentulous ridge expansion technique: A five-year study. Int J Periodontics Restorative Dent 1994;14:451-459

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