Alternative Approach to Mandibular Horizontal Ridge ... - JIACD.com

V olume 4, N o. 5

N ovember/December 2012

The Journal of Implant & Advanced Clinical Dentistry

Alternative Approach to Mandibular Horizontal Ridge Augmentation

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The Journal of Implant & Advanced Clinical Dentistry Volume 4, No . 5 • N ovember/December 2012

Table of Contents

19 Gingival Flap Attachment

Healing with Amnion-Chorion Allograft Membrane: A Controlled, Split Mouth Case Report Replication of the Classic 1968 Hiatt Study Dan Holtzclaw, H. Fritz Hinze, Nicholas Toscano

27 A Less Invasive Approach To

Mandibular Horizontal Ridge Augmentation Using Autogenous Bone: A Human Histological Case Series Diego Capri, Hyman Smukler, Luca Landi

39 R estoration of Maxillary Incisors with an Innovative Biomimetic Implant System: A Case Report Mariano A. Polack


• 5

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Table of Contents

53 Sinus Lift Procedure in

Presence of Mucosal Cyst: A Clinical Prospective Study C. Maiorana, M. Beretta, M. Benigni, M. Cicciù, E. Stoffella, GB Grossi

63 Influence of the

Crown-To-Implant Ratio on Crestal Bone Loss Oswaldo Andreé Cáceres La Torre, Jorge Noriega Castañeda, Miguel Angel Coz Fano

77 Use of Periosteal Pedicle as an

Alternate Modality for Coverage of Gingival Recession Defects: A Case Series Major B. Harshavardhana, Colonel S. K. Rath, Lieutenant Colonel Manish Mukherjee

87 Classification and treatment

plans of peri-implant soft tissue recession at the anterior zone Masana Suzuki, Junya Okawara, Yorimasa Ogata


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The BellaTek™ Encode® Impression System Wins the Pride Institute’s “Best of Class” Award

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ow in its fourth year, the Pride Institute’s Best of Class Technology Award recognizes products that demonstrate excellence in their category. The BellaTek Encode Impression System from BIOMET 3i has won this award and is considered “Best of Class.” “We are very excited about the recognition the BellaTek™ Encode® Impression System is receiving,” says BIOMET 3i President, Maggie Anderson. “This state-of-the-art technology that allows you to create a definitive abutment with just a simple impression of the healing abutment is helping clinicians around the globe reduce chair time and improve the experience for the patient. With the inclusion of intraoral scanning, there is no ‘goop’. Just one, simple, precise impression, creating a beautiful, natural restoration.” A panel, comprised of leading voices in dental technology, comes together each year to discuss, debate and decide what products merit recognition. Organized by Dr. Lou Shuman, President of Pride Institute, the panel is committed to a selection method that is unbiased and rigorous. While panelists who receive compensation from dental companies are allowed to advocate for products those companies manufacture, they are prevented from voting for those technologies. This facilitates a dynamic process that, year-to-year, honors products obscure and well-known, basic and aspirational. “The technology space has exploded in terms of quantity and quality of available products,” says Dr. Lou Shuman, DMD, CAGS, President of Pride Institute. “With the potential for a consid-

erable investment amount, it was important that someone step up and provide the corporate and dental communities with an unbiased selection process, led by technology key opinion leadership, with the sole focus of providing true guidance. That was the vision and it has come to fruition thanks to the support of the panel, ADA, Dental Products Report, and Dental Economics.” The panel consists of seven dentists with significant knowledge of and experience in dental technology, including Dr. Shuman; John Flucke, DDS, writer, speaker and Technology Editor for Dental Products Report; Paul Feuerstein, DMD, writer, speaker and Technology Editor for Dental Economics; Titus Schleyer, DMD, PhD, Associate Professor and Director, Center for Dental Informatics at the University of Pittsburg, School of Dental Medicine; Marty Jablow, DMD, author, speaker, technology consultant, and columnist for Dr. biCuspid; Parag Kachalia, DDS, Director of New Technology at the University of the Pacific, School of Dentistry; and Larry Emmott, DDS, technology writer, speaker and dental marketing consultant. “I feel very fortunate that a panel of this magnitude has agreed to contribute to the selection process,” says Dr. Shuman. The Pride Institute Best of Class Technology awards were launched in 2009 as a new concept to provide an unbiased, non-profit assessment of available technologies in the dental space. Through print and digital media coverage, the “Best of Class” message reaches the community of 150,000 dentists through multiple touchpoints—in print and online—


• 9

educating them about the products. Honoree participation in the “Tech Expo” at the American Dental Association’s Annual Session offers faceto-face interaction with the companies as well as technology-centered education provided by members of the panel as well as the esteemed consultants of Pride Institute. Courses at last year’s 2011 meeting sold out. This year’s event will be held October 18-21 in San Francisco. About BIOMET 3i BIOMET 3i LLC, is a leading manufacturer of dental implants, abutments and related products.

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Vol. 4, No. 5

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November/December 2012

Since its inception in 1987, BIOMET 3i has been on the forefront in developing, manufacturing and distributing oral reconstructive products, including dental implant components and bone and tissue regenerative materials. The company also provides educational programs and seminars for dental professionals around the world. BIOMET 3i is based in Palm Beach Gardens, Florida, with operations throughout North America, Latin America, Europe and Asia-Pacific. For more information about BIOMET 3i, please visit www.biomet3i. com or contact the company at (800) 3425454; outside the U.S. dial (561) 776-6700. ●

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Publisher SpecOps Media, LLC Design Jimmydog Design Group www.jimmydog.com Production Manager Stephanie Belcher 336-201-7475 Copy Editor JIACD staff Digital Conversion NxtBook Media Internet Management InfoSwell Media Subscription Information: Annual rates as follows: Non-qualified individual: $99(USD) Institutional: $99(USD). For more information regarding subscriptions, contact [email protected] or 1-888-923-0002. Advertising Policy: All advertisements appearing in the Journal of Implant and Advanced Clinical Dentistry (JIACD) must be approved by the editorial staff which has the right to reject or request changes to submitted advertisements. The publication of an advertisement in JIACD does not constitute an endorsement by the publisher. Additionally, the publisher does not guarantee or warrant any claims made by JIACD advertisers. For advertising information, please contact: [email protected] or 1-888-923-0002 Manuscript Submission: JIACD publishing guidelines can be found at http://www.jiacd.com/author-guidelines or by calling 1-888-923-0002.

Copyright © 2012 by SpecOps Media, LLC. All rights reserved under United States and International Copyright Conventions. No part of this journal may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying or any other information retrieval system, without prior written permission from the publisher. Disclaimer: Reading an article in JIACD does not qualify the reader to incorporate new techniques or procedures discussed in JIACD into their scope of practice. JIACD readers should exercise judgment according to their educational training, clinical experience, and professional expertise when attempting new procedures. JIACD, its staff, and parent company SpecOps Media, LLC (hereinafter referred to as JIACD-SOM) assume no responsibility or liability for the actions of its readers. Opinions expressed in JIACD articles and communications are those of the authors and not necessarily those of JIACDSOM. JIACD-SOM disclaims any responsibility or liability for such material and does not guarantee, warrant, nor endorse any product, procedure, or technique discussed in JIACD, its affiliated websites, or affiliated communications. Additionally, JIACD-SOM does not guarantee any claims made by manufact-urers of products advertised in JIACD, its affiliated websites, or affiliated communications. Conflicts of Interest: Authors submitting articles to JIACD must declare, in writing, any potential conflicts of interest, monetary or otherwise, that may exist with the article. Failure to submit a conflict of interest declaration will result in suspension of manuscript peer review. Erratum: Please notify JIACD of article discrepancies or errors by contacting [email protected] JIACD (ISSN 1947-5284) is published on a monthly basis by SpecOps Media, LLC, Saint James, New York, USA.


• 13

DID YOU KNOW? Roxolid implants deliver more treatment options Roxolid is optimal for treatment of narrow interdental spaces.

Contact Straumann Customer Service at 800/448 8168 to learn more about Roxolid or to locate a representative in your area. www.straumann.us

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Founder, Co-Editor in Chief Dan Holtzclaw, DDS, MS

Founder, Co-Editor in Chief Nicholas Toscano, DDS, MS

Editorial Advisory Board Tara Aghaloo, DDS, MD Faizan Alawi, DDS Michael Apa, DDS Alan M. Atlas, DMD Charles Babbush, DMD, MS Thomas Balshi, DDS Barry Bartee, DDS, MD Lorin Berland, DDS Peter Bertrand, DDS Michael Block, DMD Chris Bonacci, DDS, MD Hugo Bonilla, DDS, MS Gary F. Bouloux, MD, DDS Ronald Brown, DDS, MS Bobby Butler, DDS Donald Callan, DDS Nicholas Caplanis, DMD, MS Daniele Cardaropoli, DDS Giuseppe Cardaropoli DDS, PhD John Cavallaro, DDS Stepehn Chu, DMD, MSD David Clark, DDS Charles Cobb, DDS, PhD Spyridon Condos, DDS Sally Cram, DDS Tomell DeBose, DDS Massimo Del Fabbro, PhD Douglas Deporter, DDS, PhD Alex Ehrlich, DDS, MS Nicolas Elian, DDS Paul Fugazzotto, DDS Scott Ganz, DMD David Garber, DMD Arun K. Garg, DMD Ronald Goldstein, DDS David Guichet, DDS Kenneth Hamlett, DDS Istvan Hargitai, DDS, MS Michael Herndon, DDS

Robert Horowitz, DDS Michael Huber, DDS Richard Hughes, DDS Mian Iqbal, DMD, MS Tassos Irinakis, DDS, MSc James Jacobs, DMD Ziad N. Jalbout, DDS John Johnson, DDS, MS Sascha Jovanovic, DDS, MS John Kois, DMD, MSD Jack T Krauser, DMD Gregori Kurtzman, DDS Burton Langer, DMD Aldo Leopardi, DDS, MS Edward Lowe, DMD Shannon Mackey Miles Madison, DDS Lanka Mahesh, BDS Carlo Maiorana, MD, DDS Jay Malmquist, DMD Louis Mandel, DDS Michael Martin, DDS, PhD Ziv Mazor, DMD Dale Miles, DDS, MS Robert Miller, DDS John Minichetti, DMD Uwe Mohr, MDT Dwight Moss, DMD, MS Peter K. Moy, DMD Mel Mupparapu, DMD Ross Nash, DDS Gregory Naylor, DDS Marcel Noujeim, DDS, MS Sammy Noumbissi, DDS, MS Arthur Novaes, DDS, MS Charles Orth, DDS Jacinthe Paquette, DDS Adriano Piattelli, MD, DDS Michael Pikos, DDS George Priest, DMD

Giulio Rasperini, DDS Michele Ravenel, DMD, MS Terry Rees, DDS Laurence Rifkin, DDS Georgios E. Romanos, DDS, PhD Paul Rosen, DMD, MS Joel Rosenlicht, DMD Larry Rosenthal, DDS Steven Roser, DMD, MD Salvatore Ruggiero, DMD, MD Henry Salama, DMD Maurice Salama, DMD Anthony Sclar, DMD Frank Setzer, DDS Maurizio Silvestri, DDS, MD Dennis Smiler, DDS, MScD Dong-Seok Sohn, DDS, PhD Muna Soltan, DDS Michael Sonick, DMD Ahmad Soolari, DMD Neil L. Starr, DDS Eric Stoopler, DMD Scott Synnott, DMD Haim Tal, DMD, PhD Gregory Tarantola, DDS Dennis Tarnow, DDS Geza Terezhalmy, DDS, MA Tiziano Testori, MD, DDS Michael Tischler, DDS Tolga Tozum, DDS, PhD Leonardo Trombelli, DDS, PhD Ilser Turkyilmaz, DDS, PhD Dean Vafiadis, DDS Emil Verban, DDS Hom-Lay Wang, DDS, PhD Benjamin O. Watkins, III, DDS Alan Winter, DDS Glenn Wolfinger, DDS Richard K. Yoon, DDS


• 15

Less pain for your patients. Less chair side time for you. 1

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For full prescribing information, please visit us online at www.osteohealth.com or call 1-800-874-2334 References: 1Sanz M, et. al., J Clin Periodontol 2009; 36: 868-876. 2McGuire MK, Scheyer ET, J Periodontol 2010; 81: 1108-1117. 3Herford AS., et. al., J Oral Maxillofac Surg 2010; 68: 1463-1470. Mucograft® is a registered trademark of Ed. Geistlich Söhne Ag Fur Chemische Industrie and are marketed under license by Osteohealth, a Division of Luitpold Pharmaceuticals, Inc. ©2010 Luitpold Pharmaceuticals, Inc. OHD240 Iss. 10/2010

Wilcko et al

Gingival Flap Attachment Healing with Amnion-Chorion Allograft Membrane: A Controlled, Split Mouth Case Report Replication of the Classic 1968 Hiatt Study

Dan Holtzclaw, DDS, MS1 • H. Fritz Hinze, DMD1 • Nicholas Toscano, DDS, MS2 Abstract Background: Whereas laminin-5 is a known glycoprotein with significant involvement in epithelial cell motility and junctional epithelium attachment and BioXclude™ amnion-chorion membrane (ACM) is known to contain significant amounts of laminin-5,it was postulated that reproduction of the Hiatt study with the addition of ACM would possibly lead to faster gingival flap attachment. Methods: A 54 year old white male with a longstanding history of generalized moderate chronic periodontal disease and a 38 pack year history of smoking consented to participation in this study. For the purposes of this case report, the maxilla was divided into right and left halves for simultaneous treatment involving minor osseous recontouring and gingival flap replacement. Prior to flap closure, one half of the maxilla had a layer of ACM placed onto exposed bone while the control side had nothing placed onto exposed bone. Tensile flap strength was measured by pull-

ing on sutures with a tensiometer at 72 hours, 1 week, 2 weeks, and 3 weeks after surgery. Results: The control side of the maxilla had simple flap displacement at 72 hours and 1 week after surgery with tension less than 1,000 grams. At 2 weeks, 1,600 grams of tension minimally displaced the flap while at 3 weeks, flap displacement did not occur and sutures pulled through the flap with 2,100 grams of tension. On the experimental ACM side of the maxilla, simple flap displacement occurred at 72 hours. At 1 week, 1,700 grams of tension minimally displaced the flap. At weeks 2 and 3, flap displacement did not occur and sutures pulled through the flap with 2,000 or more grams of tension. Conclusion: This human case report with a split mouth controlled design demonstrated faster gingival flap attachment with addition of ACM.

KEY WORDS: Periodontal surgery, wound healing, amnion-chorion, case report 1. Private practice limited to periodontics and dental implants. Austin, Texas, USA. 2. Private practice limited to periodontics and dental implants. New York, New York, USA.


• 19

Holtzclaw et al

Background Although they are relatively new to the practice of dentistry having been recently introduced in 2008, placental allografts have been used in medicine for over 100 years with initial use in skin wound applications in the early 1900’s.1 While the first version of dental placental allograft was composed of dehydrated amnion alone, second generation dental placental allografts are composed of cryopreserved, dehydrated amnionchorion laminate (BioXclude™, Snoasis Medical, Denver, Colorado, USA). Placental barriers such as amnion-chorion membranes (ACM) demonstrate many unique properties. First and foremost, ACM’s possess a variety of proteins which provide a bioactive matrix to facilitate wound healing including collagen types I, III, IV, V, and VI,2 laminin-5, platelet derived growth factors alpha (PDGF-α) and beta (PDGF-β), FGF, and TGF-β.3 With the current knowledge that ACM’s possess a wide array of proteins, it is not surprising that skin wound healing studies of the early 1900’s noted improved healing with placental dressings. In 1968, Hiatt and colleagues4 published a study that evaluated gingival healing following replaced flap surgery. This classic wound healing study utilized sixteen older mongrel dogs with periodontal disease as test subjects. Each dog had a mucoperiosteal flap raised bilaterally over maxillary canines, alveolar bone adjusted, roots planed, and the flaps replaced with sutures. The animals were sacrificed at 48 hours, 72 hours, 1 week, 2 weeks, 3 weeks, 1 month, 4 months, 6 months, and 12 months after surgery. Immediately prior to sacrifice, the strength of flap attachment at each surgical site was tested by pulling suture loops with a tensiometer. Following sacrifice, block sections of the maxillary

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canines were histologically examined. Tensiometer data and histologic findings from this study noted that initial flap “reattachment” occurred within 1 week following surgery and strengthened during the second week to the point where retained epithelial cells were noted on the root surfaces following mechanical flap separation. Whereas laminin-5 is a known glycoprotein with significant involvement in epithelial cell motility and junctional epithelium attachment5,6 and BioXclude™ is known to contain significant amounts of laminin-5,7 it was postulated that reproduction of the Hiatt study4 with the addition of ACM would possibly lead to faster gingival flap attachment. As such, the purpose of this investigative case report was to test the effects of ACM on the strength of gingival flap attachment following replaced flap surgery.

Case Report A 54 year old white male with a longstanding history of generalized moderate chronic periodontal disease and a 38 pack year history of smoking consented to participation in this study. The study was conducted in accordance with the Declaration of Helsinki as revised in 2008. For the purposes of this case report, the maxilla was divided into right and left halves for simultaneous treatment. Following the administration of local anesthesia, full thickness mucoperiosteal flaps were elevated on both sides of the maxilla. Degranulation with ultrasonic and hand instruments was followed by calculus removal and root planing. Negative osseous architecture was corrected with rotary and hand instrumentation. Following copious irrigation with sterile saline, the right half of the maxilla had flap replacement with simple interrupted 4-0 PTFE sutures while

Holtzclaw et al

Figure 1: Amnion-chorion membrane (BioXclude™, Snoasis Medical, Denver, Colorado, USA) trimmed prior to placement on experimental side of the maxilla.

Figure 2: ACM membrane placed on exposed bone of experimental side of the maxilla prior to gingival flap replacement.

Figure 3: Suture pull with tensiometer at 1 week healing.

the left half of the maxilla had a single layer of ACM (BioXclude) placed onto exposed bone surfaces (figure 2) prior to flap replacement in a similar fashion. The patient was provided pain medications and 0.012% chlorhexidine rinse following surgery. Follow up visits were performed at 72 hours, 1 week, 2 weeks, and

3 weeks after surgery. At each post-surgical visit, following oral hygiene instructions and deplaquing of the teeth with hand instruments, loops of the sutures retaining the gingival flaps were attached to a hooked tensiometer (figure 3) (American Weight, Norcross, Georgia, USA). Gentle tension was applied to the


• 21

Holtzclaw et al

Table 1: Tensile strength (in grams) required to seperate gingival flap from underlying structures

72 hours

1 week

2 weeks

3 weeks

Control side (No ACM)

200

350

1,600

2,100*

Experimental Side (ACM added)

325

1,700

2000*

2,200*

*Denotes sutures that pulled through the ginival flap without displacing flap from underlying structures

suture loop until either the flap displaced from the underlying bone or the suture was pulled free from the gingival tissue. Following removal of all sutures, the patient was placed in periodontal maintenance at 3 month intervals.

Results The results of suture tensiometer testing are listed in table 1. On the non-ACM side of the maxilla, gingival flap displacement occurred at 72 hours and 1 week following surgery. At 2 weeks following surgery, significant resistance to suture pulling was encountered prior to the suture pulling through the flap, but a small amount of gingival flap displacement was noted. No flap displacement occurred 3 weeks following surgery. On the ACM side of the maxilla, gingival flap displacement occurred at 72 hours after surgery. At one week after surgery, significant resistance to suture pulling was encountered, but a small amount of gingival flap displacement was noted as sutures pulled through the flap. No flap displacement occurred 2 or 3 weeks following surgery.

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Discussion Wound healing is commonly divided into three stages: inflammation, granulation tissue formation, and matrix formation/remodeling.8 When dealing with the healing of a periodontal flap, phases have been classified as: adaptation, proliferation, attachment, and maturation.9 Adaptation The flap adaptation phase occurs between days 0-4 following surgery.9 Within the first few hours of surgery, this process begins with the formation of a fibrin clot between the bone and connective tissue of the overlying gingival flap. During this time, early inflammation ensues with the release of polymorphonucleosites (PMN’s), macrophages, and mast cells. The inflammatory process clears necrotic cells to provide an avenue for epithelial cell migration over connective tissue. Sabag et al.10 noted that epithelial migration begins in gingival wounds 2 days after surgery. This may occur by epithelial cells dissolving their hemidesmosomal attachment to release from the basement membrane and begin migration from wound edges.11 In

Holtzclaw et al

Table 2: Immunohistochemical analysis of amnion-chorin membrane and porcine collagen membrane Amnion Chorion (BioXcludeTM) Porcine Collagen (BioGide®)

Laminin

Laminin-5

TGF

FGF

PDGF

PDGF

4.4 ± 0.55 (p < 0.001)

4.2 ± 0.45 (p < 0.001)

1.4 ± 0.9 (p < 0.05)

0.7 ± 0.45 (p < 0.05)

2.4 ± 0.55 (p < 0.005)

3.2 ± 1.1 (NS)

0.0

0.0

0.0

0.0

0.0

3.0 ± 0.0

examining healing of pedicle flaps, Wilderman and Wentz9 noted that between 2 to 4 days after surgery, epithelial cells were in contact with the tooth. They also noted that epithelial cells migrated from wound edges at a rate of 0.5mm per day and that the fibrin clot was absent at the sites of epithelial proliferation. Proliferation The proliferation phase of gingival flap healing occurs between 4 to 21 days after surgery with the greatest mitotic activity occurring at day 4.9 At this time, blood supply to the healing wound improves as capillary loops begin anastomosing with cut vessels of the overlying gingival flap.12 Osteoclastic activity begins around days 3 to 4, reaching peak activity 8 to 10 days after surgery. This resorptive process creates a surface in which collagen fibrils of the hard tissue matrix become denuded, establishing a suitable substrate for newly forming collagen

fibrils.13 During this phase, granulation tissue invades the fibrin clot with fibroblasts appearing at days 6 to 10. The proliferating tissue seen at this time contains many capillaries, fibroblasts, lymphocytes, and PMN’s.9 Collagen formation begins at days 7 to 21. Ravanti et al.11 noted that gingival fibroblasts release matrix metalloproteinase 13 (MMP-13) to break down granulation tissues. Between days 10-14, significant amounts of epithelial migration are seen along the root creating an epithelial cuff. By this time, epithelial attachment is strong enough to resist flap displacement.4 Osteoblastic activity also begins around this time as well.14 Attachment The attachment phase of gingival flap healing occurs between days 21 to 28 after surgery9 with continued collagen formation apical to the newly formed epithelial cuff. The 1968 Hiatt study4 demonstrated that by this time,


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the fibrin clot of early healing had been largely replaced with immature collagen fibers. Apical epithelial migration no longer occurs during this phase and is thought to be limited by recently formed cementoid on the root surfaces which is typically seen by week 3 of healing.9 At this point of healing, fibroblasts and collagen fibers are parallel to the root and bone surfaces. By the end of the attachment phase, healing of the epithelial cuff has progressed to a point where flap separation does not occur, even under severe tension.4 Maturation The maturation phase of gingival flap healing occurs between days 28 to 180 after surgery.9 During this time, increased cementum and bone formation occurs along with maturation of connective tissue and connective tissue fiber bundles. By one month after surgery, osteoblastic activity reaches its peak, although slight bone apposition has been seen 6 months later.14 By 6 months onward, newly formed cementum has matured, newly formed bone has developed periosteum, and collagen fiber bundles are arranged and inserted at right angles, as compared to the earlier parallel arrangement. This case report sought to replicate the 1968 Hiatt study4 in a human clinical setting with the addition of amnion-chorion allograft membrane (ACM). Utilizing a controlled split mouth design with simultaneous surgery in a single individual allowed for direct comparison between healing with and without the addition of ACM. Gingival flap attachment, to the point where displacement by pulling on suture loops did not occur, appeared to be nearly twice as fast on the ACM side of the maxilla and with-

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stood significantly more tension pull at earlier time frames. This may be due to the significant amounts of laminin and laminin-5 in the ACM product BioXclude™. In comparing BioXclude™ to a widely available porcine collagen membrane (table 2), Xenoudi and Lucas7 found substantial amounts of laminin and laminin-5 in the ACM product and no traces of these glycoproteins in the porcine product. Laminin and laminin-5 are glycoproteins with significant involvement in epithelial cell motility and junctional epithelium attachment.5,6 The addition of ACM prior to closure of a gingival flap may allow for faster epithelial migration and subsequent initial flap attachment. Epithelial migration starts at 2-4 days following surgery and is greatest in an apical direction along the root surface 10-14 days after surgery.9 Hiatt4 noted sufficient epithelial cell attachment at this point to resist gingival flap displacement under tension. It is important to note that all of these studies were performed on dogs, a species that is widely known to heal significantly faster than humans. In the present case report, gingival surgery with the addition of ACM resulted in substantially reduced healing times in terms of flap adaptation and attachment. On the ACM side of the maxilla, gingival flap displacement occurred at 72 hours after surgery. This is understandable as during the first 72 hours, clearance of necrotic debris, fibrin clot formation, and initial epithelial migration begins. At one week after surgery, significant resistance to suture pulling was encountered, but a small amount of gingival flap displacement was noted as sutures pulled through the flap. It is important to note that while some minor flap displacement occurred with suture pulling at one week

Holtzclaw et al

following surgery, flap attachment was strong enough to require that the sutures be pulled completely through the flap in order to facilitate this displacement. In the 1968 Hiatt study,4 at one week following surgery, similar findings were observed and microscopic examination of the gingival flap “torn from the tooth” revealed intraepithelial tears with no epithelial cells remaining on the root surface. In the present case repot, no flap displacement occurred 2 or 3 weeks following surgery with suture pulling. These findings are significantly different from the non-ACM side of the maxilla in this case report which took nearly twice as long to achieve similar results as the ACM side of the maxilla.

Conclusion This human case report with a split mouth controlled design demonstrated faster gingival flap attachment with addition of ACM. Additional controlled studies with histologic analysis are recommended to expand upon and confirm these findings. ● Correspondence: Dr. Dan Holtzclaw 711 W. 38th Street • Suite G5 Austin, TX 78705 USA [email protected]

Disclosure Dr. Holtzclaw has a financial interest in Snoasis Medical and is a member of its clinical advisory board.

5. Kinumatsu T, Hashimoto S, Muramatsu T, Sasaki H, Jung HS, Yamada S, Shimono M. Involvement of laminin and integrins in adhesion and migration of junctional epithelium cells. J Periodontal Res 2009;44(1):13-20.

References 1. D avis J. Skin transplantation with a reivew of 550 cases at the Johns Hopkins Hospital. Johns Hopkins Med J 1910; 15: 307-396.

6. Masaoka T, Hashimoto S, Kinumatsu T, Muramatsu T, Jung HS, Yamada S, Shimono M. Immunolocalization of laminin and integrin in regenerating junctional epithelium of mice after gingivectomy. J Periodontal Res 2009;44(4):489-495.

2. H odde J. Naturally occurring scaffolds for soft tissue repair and regeneration. Tissue Eng 2002; 8:295-308. 3. K oizumi N, Inatomi T, Sotozono C, Fullwood N, Quantock A, Kinoshita S. Growth factor mRNA and protein in preserved human amniotic membrane. Curr Eye Res 2000;20:173-177. 4. H iatt W, Stallard R, Butler E, Badgett B. Repair following mucoperiosteal flap surgery with full gingival retention. J Periodontol 1968; 39:11-16.

7. Xenoudi P, Lucas M (2011). Immunohistochemistry Analysis of Amnion Chorion and Porcine Membranes. Poster presentation #146797 at International Association of Dental Research Annual Meeting, March 2011, San Diego, California. 8. Wikesjo U. Selvig K. Periodontal wound healing and regeneration. Periodontol 2000 1999;19:21-39.

abag N, Mery C, García M, Vasquez V, Cueto 10. S V. Epithelial reattachment after gingivectomy in the rat. J Periodontol 1984;55(3):135-141. 11. Ravanti L, Häkkinen L, Larjava H, Saarialho-Kere U, Foschi M, Han J, Kähäri VM. Transforming growth factor-beta induces collagenase-3 expression by human gingival fibroblasts via p38 mitogen-activated protein kinase. J Biol Chem 1999;274(52):37292-37300. 12. C utright D. The proliferation of blood vessels in gingival wounds. J Periodontol 1969;40:137-141. 13. Selvig K, Bogle G, Claffey N. Collagen linkage in periodontal connective tissue reattachment. An ultrastructural study in beagle dogs. J Periodontol 1988;59(11):758-768. 14. Wilderman M, Pennel B. Histogenesis of repair following osseous surgery. J Periodontol 1970;41:551-565.

9. Wilderman M, Went F. Repair of dentogingival defect with a pedicle flap. J Periodontol 1965;36:218-231.


• 25

performance in more applications. case study 1

Missing maxillary lateral incisor

case study 2

Severely atrophic maxillary ridge

OraGraft® Mineralized Cortical Particulate

Following treatment with a reinforced membrane and Facial view of case oraGraft® mineralized cortical particulate (occlusal view) prior to implant placement

implant placement complete

OraGraft® Ilium Strip Block & OraGraft® Mineralized Cortical Particulate

Placement of oraGraft® ilium strip Block with fixation crews

oraGraft® mineralized cortical particulate

Completed case following implant placement

Case study photos courtesy of Dr. Dan Holtzclaw and Dr. nicholas Toscano.

• Structural Bio-implants • Particulates • Soft Tissue/Membranes To learn more about OraGraft, contact a LifeNet Health representative at (888) 847-7831.

www.OraGraft.com EX-10-019

R

Wilcko et al

A Less Invasive Approach To Mandibular Horizontal Ridge Augmentation Using Autogenous Bone: A Human Histological Case Series

Diego Capri, DDS1 • Hyman Smukler, BDS, DMD2 • Luca Landi, DDS3 Abstract

O

ver the years several techniques have been designed to augment atrophic ridges. The approach presented here, using a series of cases for horizontal ridge augmentation, utilizes autogenous bone procured from the recipient site. The employed regenerative procedure, previously

described by the authors, eliminates the need for a distant donor area reducing the potential morbidity. A biodegradable collagen barrier (Ossix) with a slow resorption profile has been successfully employed. Clinical, radiographic and histological results confirm the validity of the selected surgical technique.

KEY WORDS: Dental implants, bone grafting, allograft, autogenous graft, GBR 1. Private Practice, Bologna, Italy 2. Professor Emeritus Department of Periodontology and Oral Biology Boston University H.M. Goldman School of Dental Medicine; Clinical Professor Department of Periodontology University of Pennsylvania School of Dental Medicine; Private practice Brookline MA 3. Private Practice; Roma, Italy


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Capri et al

INTRODUCTION To meet the esthetic needs of today’s patients and provide the restorative dentist with prosthetically driven implants, we must be able to recreate an ideal form of the soft and hard tissues that will allow us to deliver a prosthesis harmonious with the adjacent teeth.1 Several techniques have been described to counteract the physiologic tendency of post-extraction alveolar bone resorption2,3 or to augment atrophic ridges.4-12 The morbidity of autogenous bone block grafts collected both intra or extra-orally to eliminate edentulous crests deformities is not insignificant.13,14 In guided bone regeneration (GBR) procedures the reported rate of membranes exposure remains high.15 GBR is based on the principles of guided tissue regeneration, where an adequate space for blood clot formation and osteogenesis is provided through the use of a physical barrier that prevents the ingress of competing nonosteogenic soft tissues.16 Several barriers, both resorbable and non-resorbable, are available on the market and the choice is still somehow controversial.5,17 In the event of wound dehiscence, the exposure of a non-resorbable e-PTFE membrane, followed by bacterial contamination, can jeopardize the result of the regenerative procedure.18 On the other hand the premature exposure of a resorbable membrane usually results in a faster rate of material degradation that negatively affects the regenerative process.19,20 The use of a biodegradable barrier with an improved resorption profile, even if exposed to the oral environment, has been successfully reported.20,21,22 In order to impede the collapse of the barrier toward the osseous defect, thus reducing the space available for regeneration, several approaches have been designed.23,24 The use of autogenous bone chips

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Figure 1: Case I - Preoperative view of the area after reflection of a full thickness flap. Note the buccolingual deficiency.

as graft material, that will also support the membrane, still represents the “gold standard” 23 for alveolar ridge regeneration applying the GBR principles. We have previously reported an innovative approach to horizontal GBR that utilizes autogenous membranous bone obtained in the recipient site, therefore eliminating the need for a donor area with the related potential morbity.25 The primary objective of the present paper is to further validate, through a series of clinical cases, a newly designed and less invasive surgical technique for mandibular horizontal ridge augmentation. The secondary purpose is to present the histological “proof of principle” that this new procedure does not substantially alter the recipient/donor site where the osteotomy is performed, while newly formed osseous tissue is generated in the area.

TECHNIQUE DESCRIPTION Upon completion of diagnosis and prognosis (health history, extra and intra-oral examination, radiographic analysis) a detailed explanation of the identified oral pathologies was given to each

Capri et al

Figure 2: Case I – The composite image shows the CT Scans before and after the regenerative procedure. Note the improved ridge morphology.

Figure 3: Case I - A 5-mm diameter implant in the proper restorative position could be placed thanks to the improved ridge morphology.

patient. As part of the overall treatment plan for all the patients it was suggested to first proceed with a GBR procedure, and subsequently place the implant/s. All the partecipants signed a specific and detailed informed consent. Under local anesthesia a full thickness flap is elevated both on the buccal and lingual sides of the mandible. After proper mobilization of the flap through periosteal vertical releasing incisions, the autogenous cortico-cancellous graft material is collected in the surgical area either through the trepanation of cores of bone laterally to the atrophic ridge and by harvesting osseous coagulum fragments lingually to the atrophic ridge. More trepanation of the recipient atrophic ridge is usually done with a small round bur. An Allograft material such as Deminaralized Bone Matrix (Lifenet, Virgina Beach, Virginia, USA) is utilized to fill the voids left after trephining the cores therefore preventing fall back of the autogenous graft into the donor sites. If needed the DBM can also further augment the volume of the autogenous graft mate-

rial. The particulate autogenous bone is gently adapted to the atrophic side of the ridge, and a properly trimmed and rehydrated type I bovine collagen membrane is carefully adapted over the graft (Ossix, Colbar R&D Ltd., Ramat Hasharon, Israel). The barrier is stabilized in place with an initial resorbable horizontal internal mattress suture, or a series of sutures for large defects. Primary closure over the regeneration area is achieved with a mixture of internal mattress and single interrupted sutures. The patient is then dismissed with proper antibiotic, germicidal and analgesic pharmacologic coverage.

HISTOLOGIC ANALYSIS For each implant site the initial osteotomy was carried out using a 2 mm trephine to harvest a bone core representative of the regenerated site. In three cases, as a control specimen, a core was taken from an untreated area in the proximity of the regenerated site for histological comparison. The bone core was rinsed with sterile saline and immediately immersed into


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Capri et al

Figure 4: Case II - Full thickness flaps were raised revealing the moderate buccolingual atrophy of the area, a residual socket not fully healed is visible. Multiple cores were obtained.

Figure 5: Case II - Two implants were placed in the regenerated area. Note the apparently calcified remnants of the Ossix barrier that could not be removed from the area.

a buffered 10% formalin fixing solution. The specimen was kept refrigerated for approximately 10 days and then sent to the Hard Tissue Laboratory of the Catholic University of Sacred Heart for decalcification and histologic analysis. Briefly, after fixation the biopsies were rinsed thoroughly and decalcified in 20% EDTA buffered to pH 7 for 10 days and then embedded in paraffin. The specimens were then sectioned longitudinally to a thickness of about 6 to 8 µm and then stained with hematoxylin and eosin and mounted on glass slides for light microscopic evaluation. A minimum of three sections were obtained for each specimen. In some specimens a Gomori staining was utilized.

right mandibular molar was extracted 6 months before, due to root fracture, and was to be replaced with a single implant supported restoration. CBCT scan evaluation of the edentulous area revealed a deficient bucco-lingual ridge (Figure 1). The regenerative procedure was accomplished as previously described 25 and healing was uneventful. A second CBCT scan of the area was obtained 6 months later (Figure 2) and revealed a significantly improved crestal morphology, which allowed for the ideal placement of a 5 mm diameter implant (Biomet 3i, Palm Beach Gardens, Florida, USA) (Figure 3). Healing was uneventful and, after uncovering, the final restoration was delivered. A histomorphometric analysis was done on the test and control specimens. For the regenerated site the Trabecular bone volume (TBV) was 42.5%, the marrow space occupied 56% of the area while a small percentage of graft material 1.5 % was measured. In the control

CASE 1 The patient was a 46-year old female in good general health with no known drug allergies. She reported to be a smoker and it was her desire to regain a healthy mouth. The first

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Capri et al

Figure 6: Case II - Histology of the regenerated area Gomori staining. A DBM particle (center of the picture in blue) is well encased in newly formed woven bone, a blood vessel is centered in his marrow space (top of the picture to the right).

Figure 7: Case II - Histology of the regenerated area, endosteal space at high magnification - Gomori staining. Cellular activity with osseous matrix apposition can be seen (lower right corner of the picture).

core the trabecular bone volume was 58.7% with a percentage of 41.3 of marrow space.

Beach Gardens, Florida, USA) were placed (Figure 5). Uncovering was performed after four and an half months of uneventful submerged and the case was later restored. The histologies in the regenerated areas were similar in showing a highly cancellous bone. DBM particles enclosed by normal lamellar osseous tissue were visible in the apical portion of the cores. At higher magnification a DBM particle was encased by newly formed woven bone while a vessel could be seen centered in his marrow space (Figure 6). Signs of cellular activity with osseous matrix apposition can be seen at high magnification on endosteal spaces (Figure 7). The control area displayed a dense lamellar bone with secondary and tertiary osteons and normal remodeling activity. The measured TBV for the regenerated cores was of 54.1% while marrow space account for 38.2% and a 7.7% of graft material was also detectable. In the control area the

CASE 2 The patient was a 59-year old female with high blood pressure pharmacologically controlled, and with no known drug allergies. She did not smoke and she was referred to receive implants in positions 29 and 30. A CBCT scan revealed a moderate bucco-lingual atrophy of the area. The regenerative procedure was then carried out according to the protocol (Figure 4). No complications occurred following surgery. After five months the patient was sent for a new CBCT scan that revealed an improved condition for implant placement. During implant surgery, some remnants of the previously implanted Ossix membrane were removed, however a significant part of the barrier appeared somehow calcified onto the regenerated area and two 4 mm diameter implants (Biomet 3i, Palm


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Capri et al

Figure 8: Case III - Full thickness flap was elevated revealing some atrophy of the edentulous ridge.

Figure 9: Case III - Nine months after the regenerative procedure remnants of the Ossix membranes could still be seen. The amount of regenerated tissue can be seen comparing with Fig 8.

trabecular bone volume was equal to 62.4% with a volume of marrow space of 37.6%.

implants (Biomet 3i, Palm Beach Gardens, Florida, USA) were placed without complications 9 months following the regenerative procedure. implant surgery remnants of the Ossix membrane could still be identified and removed (Figure 9). After 3.5 months of uncomplicated healing a second stage surgery was performed and the case was later finalized (Figure 10). The histology of the regenerated ridge revealed some DBM particles surrounded by newly formed lamellar osseous tissue (Figure 11). The bone in the area was rich in marrow spaces with dispersed signs of new bone formation on the endosteal side. No signs of inflammation could be detected. The control sample revealed normally arranged compact lamellar bone. The histomorphometric analysis revealed a mean trabecular bone volume of 50.8% with a 40.9% of mean marrow space and a 8.3% of DBM. The control core presented a 72.4% of trabecular bone volume and a 27.6% of marrow space.

CASE 3 A 55-year old female smoker in good general health with no allergies came to our office for comprehensive dental treatment. She presented with old ill-fitting fixed partial dentures. In the fourth quadrant the distal end abutment could not be saved, due to severe periodontitis, and it was decided to temporarily retain it to maintain a provisional prosthesis in the area while implant treatment was completed. Two implants were thus planned for positions 30 and 31. The patient was sent for CBCT scan and the ridge was found to be moderately deficient in the bucco-lingual dimension (Figure 8). The GBR procedure was accomplished without complications and healing was uneventful. After maturation of the graft a second CBCT scan confirmed an improved situation for implant placement. Two 4 mm diameter

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Capri et al

Figure 10: Case III - Clinical view of completed case at a 4-year follow up. (Prosthodontist: Dr. Nicola Perakis).

Figure 11: Case III - Histology of the regenerated area Gomori staining. A DBM particle (center of the picture in blue) is well encased in newly formed bone. The green color indicates areas of recent bone apposition.

CASE 4 A non smoking female patient 42 years old, in good general health and with no allergies, presented with the chief complaint of restoring the masticatory function in the fourth quadrant (Figure 12). Implant therapy was suggested to restore the missing dental elements. She was sent for a CBCT scan and the ridge appeared moderately resorbed in the bucco-lingual dimension. Osseous regeneration was then performed. Healing was uncomplicated and the patient was referred for a second CBCT scan five months after surgery. The ridge morphology in the radiograph was now more favorable and two 4-mm diameter implants (Biomet 3i, Palm Beach Gardens, Florida, USA) were placed uneventfully eight months following GBR. The patient did not present problems during the healing period, and uncovering of the two fixtures was accomplished after three months. The final restorations were later delivered (Figure 13). The histologies performed in

the area of the implants in positions 30 and 31 showed a compact layer of cortical bone with underlying normal cancellous spaces and few remnants of DBM. The particles of DBM were found included in newly formed normal osseous tissue that displayed a mature lamellar organization with visible osteons and osteocytes in their lacunae. The irregular shape of a DBM particle could be suggestive of active remodeling taking place at its periphery (Figure 14). The histomorphometric evaluation of the osteotomy areas reported a mean trabecular bone volume of 56.5% with a mean marrow area of 40.8% and a remaining volume of 2.7% of graft material.

DISCUSSION The clinical report confirms the validity of a previously described surgical approach to horizontal guided bone regeneration.25 For all of the presented patients, the regenerative technique improved the morphology of the edentulous ridge, thus allowing for a more ideal


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Capri et al

Figure 12: Case IV - Clinical view of preoperative situation.

Figure 14: Case IV - Histology of the regenerated area - Hematoxylin and eosin stain. DBM particles encased in mature lamellar bone; the irregular shape of the DBM particle (left side of the picture) may be suggesting of active remodeling.

implant placement. Better positioning of the fixtures allowed for final restorations with better emergence profiles, and as a result, the overall harmony of the implant-supported prosthesis in relation to the adjacent and opposing dental elements was enhanced. While it might be argued that the esthetic benefit was super-

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Figure 13: Case IV - Clinical view of completed case. (Prosthetics by Dr Alessandro Cantagalli)

fluous in the non-esthetic areas, it is easy to appreciate how a better emergence profile may improve the ease of both home and professional hygiene maintenance procedures, thus reducing the potential for future biological complications.26 A more favorable implant location under the occlusal table, and a better orientation of the fixtures could also be obtained, allowing for a reduction of negative bending moments that could cause over time several biomechanical complications.27 The adopted regenerative technique presents several advantages when compared with other surgical procedures designed to rebuild lost osseous structure.4-17,23,24 A significant portion of the graft material was constituted by autogenous bone of intra-membranous origin, that could be obtained “on site” without invading more remote donor areas. Additionally, according to the proposed technique, the demineralized bone matrix was mainly, if not only, utilized to fill the voids left by the trephining action so that the procured autogenous material could not fall back in to the donor

Capri et al

sites. In doing so we lightly packed the osteoconductive and osteoinductive DBM material3,23,24 within the confines of circumferential non-through and through defects with a diameter of 3.2 mm, which were already below the critical size defect dimension,28 hence having a high spontaneous regenerative potential that could be further improved by the DBM. At the same time the gold standard autogenous graft, characterized not only by its osteoconductivity and osteoinductivity but also by its osteogenic properties,23,29 was placed where most needed on the atrophic side of the ridge, where the regenerative potential is reduced. The grafted area was then protected by the use of a resorbable collagen membrane that had previously been reported to be equally effective as an e-PTFE non-resorbable barrier.20 The obvious advantage in using a biodegradable type of material is related to the non-necessary surgical removal of the barrier and furthermore to the significantly reduced risk of post-operative infection in case of membrane exposure.20 The manufacturer’s claims regarding the improved resorption profile of the Ossix membrane (Colbar R&D Ltd., Ramat Hasharon, Israel), already confirmed by another case series,21 was verified in two of the four reported cases, where the membrane could still be seen after 5 and 9 months from the material implantation. It has been the experience of the authors that the biodegradation of this newly patented crossed linked collagenous material is indeed slower than others biodegradable membranes therefore allowing for a longer barrier effect. The bovine origin of the collagen used in the manufacturing of the Ossix membrane has been abandoned in favor of porcine collagen with the

launch of the Ossix Plus material (Colbar R&D Ltd., Ramat Hasharon, Israel), for which complete ossification of the membrane has been reported in a dog study by others.30 The same phenomenon was clinically found by the authors in the second patient here presented. To our knowledge this is the first human report of such an event in a GBR procedure. Unfortunately in spite of the positive results reported by the authors and others20,21,22,25,30 on the use of the Ossix and Ossix Plus barrier, the production of this material has been recently discontinued. The histologies obtained in the implant osteotomies showed no signs of inflammation thus supporting the good compatibility of the implanted biomaterials. In general the test areas were more cancellous than the control sections, with bone displaying a higher cellularity when compared to the controls, suggesting a more recent origin of the tissue. The bone in the regenerated areas was already organized in a lamellar fashion with few dispersed primary osteons indicating a young but already well-structured tissue; signs of new bone formation with osteoblasts actively forming osseous matrix could be seen on the endosteal surfaces. Several DBM particles were nicely encased by newly generated bone confirming the well-known osteoconductive property of the allograft. The shape of some particles was quite jagged probably as a result of the slow remodeling of the material. The histomorphometric evaluation done on all the histological test samples collected was averaged out giving an overall mean value of trabecular bone volume of 50.9% (SD ± 6.1%); the overall mean volume of marrow was equal to 43.9% (SD ± 8.1%), while the remaining mean DBM graft material was 5%


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Capri et al

(SD ± 3.4%) . For the control specimens the figure were: mean TBV of 64.5% (SD ± 7%), mean marrow space volume equal to 35.5% (SD ± 7%). In conclusion the clinical, radiographic and histological results presented in this series of cases support the use of the previously reported modified guided bone regenerative procedure25 as a valid method to achieve improved implant placement with a more satisfying prosthetic outcome. ● Disclosure The authors report no conflicts of interest. References 1. S mukler H, Castellucci F, Capri D. The role of the implant housing in obtaining aesthetics: Generation of peri-implant gingivae and papillaePart I. Pract Proced Aesthet Dent 2003; 15: 141-149. 2. S chropp L, Wenzel A, Kostopoulos L, Karring T. Bone healing and soft tissue contour changes following single-tooth extraction: A clinical and radiographic 12-month prospective study. Int J Periodontics Restorative Dent. 2003 Aug; 23(4):313-23. rugnami F, Then PR, Moroi H, Kabani S, Leone 3. B CW. GBR in human extraction sockets and ridge defects prior to implant placement: clinical results and histologic evidence of osteoblastic and osteoclastic activities in DFDBA. Int J Periodontics Restorative Dent 1999; 19: 259267. yman S, Lang NP, Buser D, Bragger U. Bone 4. N regeneration adjacent to titanium dental implants using guided tissue regeneration: a report of two cases. Int J Oral Maxillofac Implants. 1990; 5: 9-14. 5. S imion M, Trisi P, Piattelli A. Vertical ridge augmentation using a membrane technique associated with osseointegrated implants. Int J Periodontics Restorative Dent 1994; 14: 496511. 6. N evins M, Mellonig JT. The advantages of localized ridge augmentation prior to implant placement: A staged event. Int J Periodontics Restorative Dent 1994; 14: 96-111. 7. M isch CE, Dietsh F. Endosteal implants and iliac crest grafts to restore severely resorbed totally edentulous maxillae--a retrospective study. J Oral Implantol. 1994; 20(2):100-110. 8. D ahlin C, Lekholm U, Becker W, Becker B, Higuchi K, Callens A, van Steenberghe D. Treatment of fenestration and dehiscence bone defects around oral implants using the guided tissue regeneration technique: a prospective multicenter study. Int J Oral Maxillofac Implants 1995; 10: 312-8. 9. M isch CM. Ridge augmentation using mandibular ramus bone grafts for the placement of dental implants: presentation of a technique. Pract Periodontics Aesthet Dent 1996; 8: 127-35.

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Correspondence: Dr. Diego Capri COBE DENTAL – Via Bazzanese 32/4, 40030 Casalecchio di Reno (Bologna-ITALY) Telephone 011-39-0516132796 Fax 011-39-0516137011 [email protected]

10. Misch CM. Comparison of intraoral donor sites for onlay grafting prior to implant placement. Int J Oral Maxillofac Implants. 1997 Nov-Dec; 12(6):767-76. 11. H unt DR, Jovanovic SA. Autogenous bone harvesting: a chin graft technique for particulate and monocortical bone blocks. Int J Periodontics Restorative Dent 1999; 19: 165-73. 12. M isch CM. Use of the mandibular ramus as a donor site for onlay bone grafting. J Oral Implantol. 2000; 26(1):42-9. 13. J oshi A, Kostakis GC. An investigation of postoperative morbidity following iliac crest graft harvesting. Br Dent J 2004; 196: 167-71 14. R aghoebar GM, Louwerse C, Kalk WW, Vissink A. Morbidity of chin bone harvesting. Clin Oral Implants Res 2001; 12: 503-7. 15. C hiapasco M, Romeo E, Casentini P, Rimondini L. Alveolar distraction osteogenesis versus vertical guided bone regeneration for the correction of vertically deficient edentulous ridges: a 1-3 year prospective study on humans. Clin Oral Implants Res 2004; 15(1): 82-95. 16. L inde A, Alberius P, Dahlin C, Bjurstam K, Sundin Y. Osteopromotion: a soft-tissue exclusion principle using a membrane for bone healing and bone neogenesis. J Periodontol. 1993; 64 (11 Suppl): 1116-28. 17. C arpio L, Loza J, Lynch S, Genco R. Guided bone regeneration around endosseous implants with anorganic bovine bone mineral. A randomized controlled trial comparing bioabsorbable versus non-resorbable barriers. J Periodontol 2000; 71:1743-9. 18. S imion M, Baldoni M, Rossi P, Zaffe D. A comparative study of the effectiveness of e-PTFE membranes with and without early exposure during the healing period. Int J Periodontics Restorative Dent 1994; 14: 166180. 19. O h TJ, Meraw SJ, Lee EJ, Giannobile WV, Wang HL. Comparative analysis of collagen membranes for the treatment of implant dehiscence defects. Clin Oral Implants Res 2003; 14(1): 80-90. 20. M oses O, Pitaru S, Artzi Z, Nemcovsky CE. Healing of dehiscence-type defects in implants placed together with different barrier membranes: a comparative clinical study. Clin Oral Implant Res 2005; 16(2): 210-9.


21. Friedman A, Strietzel FP, Meretzki B, Pitaru S, Bernimoulin JP. Observation of a new collagen barrier membrane in 16 consecutively treated patients. Clinical and histological findings. J Periodontol 2001; 72: 1616-1623. 22. Friedmann A; Strietzel FP; Maretzki B; Pitaru S; Bernimoulin JP. Histological assessment of augmented jaw bone utilizing a new collagen barrier membrane compared to a standard barrier membrane to protect a granular bone substitute material. Clin Oral Implants Res 2002 Dec; 13(6):587-94. 23. Simion M, Dahlin C, Trisi P, Piattelli A. Qualitative and quantitative comparative study on different filling materials used in bone tissue regeneration: a controlled clinical study. Int J Periodontics Restorative Dent 1994; 14: 198-215. 24. Smukler H, Landi L, Setayesh R. Histomorphometric evaluation of extraction sockets and deficient alveolar ridges treated with allograft and barrier membrane: a pilot study. Int J Oral Maxillofac Implants 1999; 14: 407-16. 25. Smukler H, Capri D, Landi L. Harvesting bone in the recipient site for ridge augmentation. Int J Periodontics Restorative Dent 2008; 28(4): 411-419. 26. Karoussis IK, Salvi GE, Heitz-Mayfield LJ, Bragger U, Hammerle CH, Lang NP. Long-term implant prognosis in patients with and without a history of chronic periodontis: a 10-year prospective cohort study of the ITI ® dental implant system. Clin. Oral Implants Res 2003; 14: 329 – 339. 27. Pjetursson BE, Tan K, Lang NP, Bragger U, Egger M, Zwahlen M. A systematic review of the survival and complication rates of fixed partial dentures (FPDs) after an observation period of at least 5 years. Clin Oral Implants Res 2004; 15(6): 625-642. 28. Thorwarth M, Schultze-Mosgau S, Kessler P, Wiltfang J, Schlegel KA. Bone regeneration in osseous defects using a resorbable nanoparticular hydroxyapatite. J Oral Maxillofac Surg 2005; 63(11): 1626-33. 29. Gross JS. Bone grafting materials for dental applications: a practical guide. Compend Contin Educ Dent 1997; 18(10): 1013-8, 1020-2, 1024. 30. Zubery Y, Goldlust A, Alves A, Nir E. Ossification of a novel cross-linked porcine collagen barrier in guided bone regeneration in dogs. J Periodontol 2007; 78: 112-121.

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1 Hodde J, Janis A, Ernst D, et al. “Effects of sterilization on an extracellular matrix scaffold: part I. Composition and matrix architecture.” J Mater Sci Mater Med. 2007;18(4):537-543. 2 Hodde JP, Ernst DM, Hiles MC.”An investigation of the long-term bioactivity of endogenous growth factor in OASIS Wound Matrix.” J Wound Care. 2005 Jan;14(1):23-5. 3. Effective Design of Bone Graft Materials Using Osteoinductive and Osteoconductive Components. Kay, JF; Khaliq, SK; Nguyen, JT. Isotis Orthobiologics, Irvine, CA (abstract). 4. Amounts of BMP-2, BMP-4, BMP-7 and TGF-ß1 contained in DBM particles and DBM extract. Kay, JF; Khaliq, SK; King, E; Murray,SS; Brochmann, EJl. Isotis Orthobiologics, Irvine, CA (white paper/abstract).

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Restoration of Maxillary Incisors with an Innovative Biomimetic Implant System: A Case Report

Wilcko et al

Mariano A. Polack, DDS, MS1 Abstract

I

mmediate surgical and restorative procedures in the esthetic zone have the potential to produce pleasing esthetic results in a shorter time. However, challenges have been reported with immediate implant placement due to the continuing recession of the facial gingival tissue. This could compromise esthetics by exposing the abutment margin or implant collar. In addition, patients with a thin biotype may not be able to conceal implant titanium adequately leading to

the grayish discoloration of the soft tissue. The implant and restorative components selected for these situations play an important role in achieving superior outcomes. A patient treated with an implant designed for immediate function has been presented. The system has a nano-rough hydrophilic active surface, a light-pink implant neck and light-pink colored abutments, which may help improve the functional and esthetic predictability of these advanced treatment modalities.

KEY WORDS: Dental implants, esthetics, prosthetics 1. Private practice, Gainesville, VA


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INTRODUCTION Recent technological advances have transformed implant dentistry. Immediate implant placement and loading can help satisfy the patient’s demand for faster results. However, these procedures are technically demanding and require adequate training to provide predictability. Several authors have reported esthetic complications with immediate implant placement in the esthetic zone, due to the continuing recession of the facial gingival tissue. 1, 2 3 In particular, patients with a thin biotype are more susceptible to gingival migration,4, 5 and their periimplant tissues may not be able to conceal implant titanium adequately.6 This could compromise the esthetic result through tissue discoloration in the cervical third,7 and the exposure of the abutment margin or implant collar. An implant with an optimized neck color that mimics the appearance of the gingiva could be beneficial, should any the above complications occur. Due to their inherent esthetic properties, zirconia abutments may improve the cosmetic outcome of implant restorations.8 However, stress distribution, surface flaws, misfit and other factors may result in the fracture of ceramic abutments,9-11 and reports of these incidents can be found in the literature.12, 13 In addition, the cost of fabrication of custom ceramic abutments can be high. Prefabricated titanium abutments are not susceptible to fracture14 or wear after cyclic loading,15 and they cost less than ceramic abutments.16 Titanium, as zirconia, is highly biocompatible, allowing for epithelial and connective tissue attachment.17 However, due to titanium’s inherent grey color, the overlying

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soft tissue may appear dark. Appropriately shaded prefabricated titanium abutments would be advantageous in avoiding these challenges and enhancing the final esthetic outcome. Recently, a new implant system (Genesis, Keystone Dental, Burlington, Massachusetts, USA) has been introduced to address these challenging situations. The implant, designed for immediate function, has a nanorough hydrophilic active surface with a light pink-colored collar. In addition, pink titanium restorative components are available to enhance the esthetic integration of the final restoration with the soft tissue. This article will present a clinical case to illustrate the benefits of this new implant system.

CASE REPORT A 66-year-old non-smoker male presented with missing teeth #9 and 10, which had been removed several years earlier (Figures 1 and 2). The patient was wearing a transitional removable partial denture. The residual ridge had undergone vertical resorption, and was apical to the gingival margins of the contralateral central and lateral incisors. Radiographic evaluation of these teeth revealed less than ideal crown to root ratios and apical radiolucencies around the apices (Figure 3). The clinical evaluation showed staining and leakage around the large composite resin restoration on tooth #7, as well as recurrent caries under the open margins of crown #8. After anesthetizing the patient, bone sounding of these teeth revealed moderate to advance facial bone loss. Study models were obtained, and a diagnostic wax-up was done simulating the replacement of teeth #9 and 10. The diagnostic wax-up was shared with the patient,

Polack

Figure 1: Preoperative extraoral view.

who objected to the lack of gingival symmetry between the right and left maxillary incisors. After discussing various treatment options, the patient elected to extract teeth #7 and 8, have two implants placed on sites #7 and 10, and replace the maxillary incisors with a four-unit implant supported fixed-partial-denture (FPD). Using the diagnostic wax-up, a clear suckdown matrix was fabricated. The maxillary incisors were removed from the model, and the corresponding areas on the matrix were filled with barium containing polymethyl methacrylate (Jet XR, Lang Dental Manufacturers, Wheeling, IL. The matrix was then seated onto the diagnostic model and placed for 15 minutes in hot water inside a pressure pot. After setting of the polymethyl methacrylate (PMMA), two parallel holes were drilled through the matrix, on the lingual side of the lateral incisors. In this manner, a scan guide that would also serve as a surgical guide was fabricated. The facial gingival margins of teeth #7 and #10 were marked on the guide with a permanent marker, to indicate the desired position of the cervical margins of the final restorations. Instructions were given to the surgeon to place implants on sites #7 and 10, approximately 3 mm api-

Figure 2: Preoperative intraoral view. Note the vertical discrepancy between the right and left sides.

Figure 3: Preoperative radiographic presentation.

cal to those markings. The patient was referred to the surgeon’s office for implant placement. Profound local anesthesia was achieved with 5.4 cc of lidocaine 2% with 1:100,000 epi-


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Figure 5: Provisional abutments after initial preparation.

Figure 6: Finished screw-retained provisional FPD.

Figure 7: The incisal edges on the provisional FPD were shortened to eliminate all occlusal contacts.

Figure 8: At the one-week postoperative appointment excellent gingival health was evident.

nephrine. Teeth #7 and 8 were removed, and a CT scan was done with the scan guide in place to confirm the position of the proposed restoration in relation to the existing bony anatomy. A crestal incision with papilla sparing releasing incisions was made to elevate a buccal flap. Using the guide, the crestal bone was reduced and scalloped in sites #7 and 8 matching the height of the edentulous ridge on the left side. The implant osteotomy was made through the guide. Two narrow diameter, 3.8x13mm implants (Genesis, Keystone Dental, Burlington, Massachusetts, USA) were placed with primary stability using the handpiece adaptor set at 35

Ncm. The prosthetic table was placed approximately 3 mm below the future cervical margin of the restoration, as determined by the surgical guide. Contoured healing abutments with a 3 mm cuff and 5 mm flare were placed. The periosteum was incised and advanced in sites #9 and 10. The buccal defects and socket gaps were grafted with a xenograft (BioOss, Geistlich Biomaterials, Princeton, New Jersey, USA) mixed with an allograft (Dynablast, Keystone Dental). An absorbable collagen wound dressing (Collaplug, Zimmer Dental, Carlsbad, California, USA) was placed over the socket graft on site #8. After gingivoplasty, the flaps

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Figure 9: The provisional FPD provided an esthetic solution while waiting for osseointegration.

Figure 10: Closed-tray impression posts with flare and contours matching those of the healing and provisional abutments were connected.

Figure 12: View of the definitive restoration and abutments prior to delivery. The pink surface on the body of the implants is removed during preparation, but remains in the critical gingival portion.

Figure 11: Prefabricated pink-anodized definitive abutments after adjustment of the margins.

were reapproximated with 4-0 chromic sutures. Radiographs were taken to confirm proper positioning in the alveolar bone and adequate seating of the healing abutments. Postoperative

instructions were discussed and the patient was referred on the same day to the prosthodontist’s office for immediate provisionalization. The healing abutments were removed and small-diameter provisional abutments (PMMA Temporary Abutments, Genesis, Keystone Dental) were connected to the implants and hand tightened (Figure 4). The flared profile of these abutments helped support the soft tissue with minimum effort. The provisional abutments were prepared to the gingival margin (Figure 5), and cotton was inserted to avoid blocking


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Figure 13: Buccal view of the definitive prosthesis with definitive abutments. The light-pink coloration of the gingival cuffs will facilitate the esthetic integration of the restoration.

Figure 14: Insertion of the prefabricated abutment. The gingival cuff’s inherent light-pink color seems to reflect the overall hue of the gingiva.

Figure 15: Facial view prior to final cementation of restoration. Should the patient ever experience gingival recession in this area, the light-pink shade on the abutments will avoid the unsightly dark hue associated with conventional metallic abutments.

Figure 16: Postoperative intraoral view shows pleasing esthetic integration. Postoperative extraoral view. Good shade match and characterization were achieved.

Figure 17: Postoperative radiograph control revealed adequate crestal bone levels to the top of the implant.

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the access hole with acrylic resin. A provisional shell fabricated from the diagnostic waxup was filled with a thin mix of acrylic resin (Jet Acrylic, Lang Dental Manufacturers) and seated over the provisional abutments. Once the acrylic polymerized, a small opening was made with a carbide bur (#557, Dentsply International, York, Pennsylvania, USA) on the lingual side of the screwretained provisional restoration. The cotton

Polack

Figure 18: Radiographs after final restoration.

was removed and the provisional unscrewed. The tissue side of the restoration was examined, and flowable composite (Tetric EvoFlow, Ivoclar Vivadent Inc., Amherst, New York, USA) was used to turn all concavities into convex surfaces. The tissue side of #8 and 9 was contoured in the shape of ovate pontics (Figure 6). Occlusal contacts in maximum intercuspation were eliminated, and the incisal edges shortened to avoid protrusive contacts (Figure 7). The provisional prosthesis was polished with flour of pumice (Whip Mix Corporation, Louisville, Kentucky, USA) and connected to the implants with a torque of 30 Ncm. The screw access hole was restored with composite resin (Esthetix, Dentsply International, York, Pennsylvania, USA), and the patient was recalled one week later. At the next visit no complications and excellent soft tissue health were observed (Figure 8). Although the incisal edges of the

immediate restoration had to be shortened to protect the osseointegration of the implants, an esthetic interim result was achieved (Figure 9). Approximately eight weeks after the provisional restoration was delivered, closedtray impression posts were connected to the implants (Figure 10). The impression posts had gingival cuff contours identical to those of the provisional abutments, providing excellent support for the emergence profile developed in the provisional phase. In this manner, the faithful reproduction of the periimplant gingiva on the master model was guaranteed. A radiograph was taken to confirm proper seating, and a final polyvinylsiloxane (Exafast, GC America, Alsip, Illinois, USA) impression was made. An occlusal registration was obtained, and the impression posts were connected to their respective analogs and replaced in the impression. Due to the proximity of the


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screw-access holes to the incisal edge on the provisional restoration, it was decided that the final FPD would be cement-retained. Prefabricated 15° angled titanium abutments (Genesis Esthetic contour Ti abutment, Keystone Dental) with an appropriate cuff height were selected. Their subgingival contours matched those of the provisional abutments and impression posts previously utilized. This would help maintain consistent soft tissue levels in the final phase of treatment. The abutments, which are anodized with a light-pink color, were seated on the master model and their margins prepared just below the gingival margin (Figure 11). A four-unit FPD metal framework was waxed and cast in a high-noble alloy. At the next appointment, the abutments and the framework were tried in. Complete seating of the metallic substructure was confirmed clinically and radiographically. The shade was captured, intraoral photographs taken, and a pick up impression with polyvinylsiloxane (Exafast, GC America) was made to integrate the periimplant gingival tissues with the emergence profile of the restoration. The FPD was sent to the laboratory for porcelain application (Figures 12, 13). Care was taken to ensure the tissue side of the pontics was ovate in contour. The definitive abutments were seated (Figure 14), torqued to 30 Ncm, (Figure 15) and their screw-access holes sealed with gutta-percha and composite resin. The restoration was tried in to examine aesthetics, interproximal contacts, occlusion, and cleansability. The FPD was cemented with a self-adhesive resin cement (Relyx Unicem 2, 3M, St. Paul, Minnesota, USA) (Figures 16, 17). Radiographic controls performed at 6

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months confirmed stable crestal bone levels to the top of the implants (Figure 18).

DISCUSSION Immediate loading protocols provide several advantages. Patients can resume normal function rapidly without the need for a removable prosthesis, and a second implant surgery is eliminated. As the number of appointments decreases, so does the total cost for the clinician, while the shorter treatment time enhances patients’ satisfaction. Three main biological aspects need to be considered for immediate loading of dental implants. These include primary stability, the enhancement of osteogenesis and the control of osteolysis.18 Primary stability, arguably the most important of the aforementioned factors, refers to limiting micromotion between the implant and new forming tissues below 150 microns.19 A minimum insertion torque of 35 Ncm seems necessary to obtain this goal.20 Careful attention to the occlusal scheme is also mandatory. Limiting and distributing occlusal contact in centric occlusion or maximum intercuspation for fully edentulous arches, and removing all centric and excursive contacts from the provisional restorations in partially edentulous arches are some of the recommendations found in the literature.21 In order to enhance osteogenesis and offset osteolysis, implants with macro, micro and nanorough topography are desirable.22, 23 Novel biomimetic treatments of the surface layer of titanium can modify both the morphology of the implant as well as the surface chemistry.24 The cell shape changes in osteoblasts produced through interaction with the modified implant topography may lead to the enhanced

Polack

differentiation of osteoblasts,25 which could enhance the implant’s short-term osseointegration potential. The implant surfaces utilized in this clinical case have been modified with a new biomimetic electrochemical procedure that involves a three-step anodic spark deposition process (ASD).26 The ASD treatment (BiosparkTM, Genesis, Keystone Dental), is sequentially done in solutions containing phosphate and calcium ions, and finished by an additional alkali-etching step. The result is a hydrophilic, nanorough surface enriched with calcium and phosphorous ions. In vitro studies have shown that this surface has improved mechanical stability and mineralization capability, as well as high bioactivity and osteoblast stimulating potential.26-28 In vivo studies have shown that bone around this surface is more mature than bone formed around sandblasted surfaces.24 Another in vivo study confirmed that this surface has the potential to substantially improve the speed and stability of osseointegration, even in osteopenic conditions.29 The implant utilized has microthreads in the transcortical region, and a microroughened collar which are important factors in the preservation of stable crestal bone levels.30, 31 these will also contribute to enhance periimplant gingival esthetics. In addition, the amorphous titanium oxide layer on the implant collar has been converted into a crystalline titanium layer enriched in anatase, one of the three possible crystalline titanium oxide microstructures.32 This is achieved through a proprietary anodization process (AnaTite Surface TreatmentTM, Keystone Dental, Burlington, Massachusetts, USA). The microstructure produces a light pink-colored surface that resembles the appearance of gin-

gival tissue, resulting in enhanced esthetics. An in vivo study confirmed that a light pink coloration on the implant neck effectively masks the grey appearance imparted to the soft tissue by the underlying titanium.33 Since there have been reports of continuing recession of the facial gingiva with immediate implant placement in the aesthetic zone,3, 34 this feature could offset the esthetic compromise caused by the potential exposure of the implant collar. Furthermore, in vitro colonization studies have shown this surface can generate a remarkable decrease in bacterial attachment,35 without negatively influencing cell metabolic activity.36 Additional studies are needed to determine the clinical antibacterial efficacy of the anatase surface. The success of immediate loading additionally relies on limiting crestal bone resorption.18 Conical or tapered connections can prevent mobility and avoid bacterial infiltration at the implant/abutment interface (“microgap”), thus minimizing bone loss and enhancing the outcome of immediate loading.37 A platformswitched restorative interface can also help manage crestal bone resorption.38 This has the additional advantage of improving support for the periimplant gingiva, having a positive effect on the final esthetic result.8 The conical platform-switched connection of the implant utilized should prove beneficial at maintaining excellent gingival esthetics over time. It is frequently claimed that zirconia abutments, in combination with ceramic crowns, may produce superior esthetic results.39, 40 The increased translucency of the restoration, and the higher value of zirconia abutments are reported to minimize gingival shadowing and contribute to a vital appearance.41 However,


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Table 1: Indications for Prefabricated Light-Pink Titanium Abutments Narrow-diameter implant platforms Patients with thin biotype where dimensions of zirconia abutments would be inadequate Patients with a thick biotype Patients with a low value shade PFM implant-supported prosthesis

several complications have been reported for these components. In a recent study, the load fatigue performance of narrow, regular, and wide-diameter ceramic abutments was evaluated.42 The authors found that narrow and regular diameter ceramic abutments are at a greater risk of fatigue failure. Fractures can also occur on zirconia abutments as a result of overpreparing and thinning of the lateral walls.13 From an esthetic standpoint, a systematic review of the literature suggests that unshaded zirconia may be too white for the esthetic zone.43 Prefabricated titanium abutments are stronger and have greater fatigue reliability than ceramic abutments.44 In addition, they are less costly16 and have shorter laboratory turnaround times. However, they are considered unesthetic because they could make the overlying gingiva appear grey.45 The literature, however, is not conclusive on this matter. Jung et al evaluated the in vitro color changes of different thicknesses of soft tissue overlying titanium and zirconia.6 The study confirmed that once the mucosa reaches a thickness of 3.0

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mm, the human eye could not distinguish changes in color between both materials. A similar in vivo study reported that gingival coloration differences between zirconia and titanium abutments are no longer noticeable when the mucosa thickness exceeds 2 mm.46 This means that in patients with a thick biotype,47 metallic abutments can be used, since the soft tissue should mask their color. A randomized control clinical trial evaluating customized zirconia and titanium abutments in the canine and posterior regions corroborated that the amount of tissue discoloration induced by the two abutment types is not significantly different.48 A zirconia abutment is usually selected when the final prosthesis will also be made with an all-ceramic material. This is supposed to result in a superior esthetic outcome compared to a metalloceramic restoration.7, 49 However, a recent clinical study found that expert clinicians were only able to identify porcelain-fusedto-metal (PFM) or all-ceramic implant crowns correctly 50% and 47% of the time, respectively.50 The authors conclude that all-ceramic and PFM single-implant restorations may be indistinguishable from each other. In addition, PFM restorations may be better able to match low value shades than all ceramic restorations.16 In the case presented here, narrow-diameter implants were used on a patient with a thick biotype and an overall low value shade. Taking into consideration the scientific literature referenced above, prefabricated titanium abutments and a PFM fixed-partial denture were selected for this patient. The abutments used are also modified with the AnaTite Surface TreatmentTM, which gives them a lightpink coloration. A recent in vivo study confirms

Polack

that light pink implant components could provide a clinically indistinguishable color difference with the surrounding gingiva, resulting in an esthetic advantage over both ceramic and conventional titanium abutments.33 In contrast, the authors found that a stark white abutment material such as zirconia may not be an optimal choice, since it could significantly increase the value of the overlying soft tissue. Possible indications for prefabricated lightpink titanium abutments are listed on Table 1.

CONCLUSIONS Immediate surgical and restorative procedures have the potential to produce pleasing esthetic results in a shorter time. However, challenges such as gingival recession and soft tissue discoloration have been reported with immediate implant placement in the esthetic zone. A system with a nanorough hydrophilic active surface, a light-pink implant neck and light-pink colored abutments may help improve the functional and esthetic predictability of these advanced treatment modalities. ●

ADVERTISE ADVERTISE WITH TODAY! Reach more customers with the dental profession’s first truly interactive paperless journal! Using recolutionary online technology, JIACD provides its readers with an experience that is simply not available with traditional hard copy paper journals.

Correspondence: Dr. Mariano Polack 7431 New Linton Hall Rd Gainesville, VA 20155 Phone: (703) 753-8753 Fax: (703)753-8994 [email protected]

WWW.JIACD.COM The Journal of Implant & Advanced Clinical Dentistry

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Disclosure The author reports no conflict of interest with anything mentioned in this article. References 1. G allucci GO, Mavropoulos A, Bernard JP, Belser UC. Influence of immediate implant loading on periimplant soft tissue morphology in the edentulous maxilla. Int J Oral Maxillofac Implants 2007;22(4):595-602. 2. G allucci GO, Grutter L, Chuang SK, Belser UC. Dimensional changes of periimplant soft tissue over 2 years with single-implant crowns in the anterior maxilla. J Clin Periodontol 2011;38(3):293-9. 3. K an JY, Rungcharassaeng K, Lozada JL, Zimmerman G. Facial gingival tissue stability following immediate placement and provisionalization of maxillary anterior single implants: a 2- to 8-year follow-up. Int J Oral Maxillofac Implants 2011;26(1):179-87. isapakultorn K, Suphanantachat S, Silkosessak 4. N O, Rattanamongkolgul S. Factors affecting soft tissue level around anterior maxillary single-tooth implants. Clin Oral Implants Res;21(6):662-70. 5. Chen ST, Buser D. Clinical and esthetic outcomes of implants placed in postextraction sites. Int J Oral Maxillofac Implants 2009;24 Suppl:186-217. 6. J ung RE, Sailer I, Hammerle CH, Attin T, Schmidlin P. In vitro color changes of soft tissues caused by restorative materials. Int J Periodontics Restorative Dent 2007;27(3):251-7. 7. W atkin A, Kerstein RB. Improving darkened anterior periimplant tissue color with zirconia custom implant abutments. Compend Contin Educ Dent 2008;29(4):238-40, 42. 8. P olack MA, Mahn DH. The use of a customized prefabricated zirconia abutment and zirconia crown in the restoration of an immediately provisionalized implant in the esthetic zone. Compend Contin Educ Dent 2008;29(6):358-62. 9. V igolo P, Fonzi F, Majzoub Z, Cordioli G. An in vitro evaluation of titanium, zirconia, and alumina procera abutments with hexagonal connection. Int J Oral Maxillofac Implants 2006;21(4):575-80. 10. Adatia ND, Bayne SC, Cooper LF, Thompson JY. Fracture resistance of yttria-stabilized zirconia dental implant abutments. J Prosthodont 2009;18(1):17-22. 11. Kosmac T, Oblak C, Jevnikar P, Funduk N, Marion L. The effect of surface grinding and sandblasting on flexural strength and reliability of Y-TZP zirconia ceramic. Dent Mater 1999;15(6):426-33. 12. Roe P, Kan JY, Rungcharassaeng K, Won JB. Retrieval of a fractured zirconia implant abutment using a modified crown and bridge remover: a clinical report. J Prosthodont;20(4):315-8. 13. Aboushelib MN, Salameh Z. Zirconia implant abutment fracture: clinical case reports and precautions for use. Int J Prosthodont 2009;22(6):616-9. 14. Luthardt RG, Holzhuter M, Sandkuhl O, Herold V, Schnapp JD, Kuhlisch E, et al. Reliability and properties of ground Y-TZP-zirconia ceramics. J Dent Res 2002;81(7):487-91. 15. Klotz MW, Taylor TD, Goldberg AJ. Wear at the titanium-zirconia implant-abutment interface: a pilot study. Int J Oral Maxillofac Implants;26(5):970-5. 16. Mahn DH, Polack MA. Comparing three abutment types with a zirconia crown in the aesthetic zone: a case report. Dent Today 2009;28(3):108, 10-1. 17. Abrahamsson I, Berglundh T, Glantz PO, Lindhe J. The mucosal attachment at different abutments. An experimental study in dogs. J Clin Periodontol 1998;25(9):721-7.

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18. C ooper LF, De Kok IJ, Rojas-Vizcaya F, Pungpapong P, Chang SH. The immediate loading of dental implants. Compend Contin Educ Dent 2007;28(4):216-25; quiz 26. 19. S zmukler-Moncler S, Salama H, Reingewirtz Y, Dubruille JH. Timing of loading and effect of micromotion on bone-dental implant interface: review of experimental literature. J Biomed Mater Res 1998;43(2):192-203. 20. B runski JB. Biomechanical factors affecting the bone-dental implant interface. Clin Mater 1992;10(3):153-201. 21. M orton D, Jaffin R, Weber HP. Immediate restoration and loading of dental implants: clinical considerations and protocols. Int J Oral Maxillofac Implants 2004;19 Suppl:103-8. 22. L e Guehennec L, Soueidan A, Layrolle P, Amouriq Y. Surface treatments of titanium dental implants for rapid osseointegration. Dent Mater 2007;23(7):844-54. ermann F, Lerner H, Palti A. Factors influencing 23. H the preservation of the periimplant marginal bone. Implant Dent 2007;16(2):165-75. 24. G iavaresi G, Fini M, Chiesa R, Giordano C, Sandrini E, Bianchi AE, et al. A novel multiphase anodic spark deposition coating for the improvement of orthopedic implant osseointegration: an experimental study in cortical bone of sheep. J Biomed Mater Res A 2008;85(4):1022-31. okubu E, Hamilton DW, Inoue T, Brunette 25. K DM. Modulation of human gingival fibroblast adhesion, morphology, tyrosine phosphorylation, and ERK 1/2 localization on polished, grooved and SLA substratum topographies. J Biomed Mater Res A 2009;91(3):663-70. 26. S andrini E, Chiesa R, Rondelli G, Santin M, Cigada A. A novel biomimetic treatment for an improved osteointegration of titanium. J Appl Biomater Biomech 2003;1(1):33-42. 27. Giordano C, Chiesa R, Sandrini E, Cigada A, Giavaresi G, Fini M, et al. Physical and biological characterizations of a novel multiphase anodic spark deposition coating to enhance implant osseointegration. J Mater Sci Mater Med 2005;16(12):1221-9. 28. S andrini E, Giordano C, Busini V, Signorelli E, Cigada A. Apatite formation and cellular response of a novel bioactive titanium. J Mater Sci Mater Med 2007;18(6):1225-37. 29. G iavaresi G, Chiesa R, Fini M, Sandrini E. Effect of a multiphasic anodic spark deposition coating on the improvement of implant osseointegration in the osteopenic trabecular bone of sheep. Int J Oral Maxillofac Implants 2008;23(4):659-68. 30. Neugebauer J, Weinlander M, Lekovic V, von Berg KH, Zoeller JE. Mechanical stability of immediately loaded implants with various surfaces and designs: a pilot study in dogs. Int J Oral Maxillofac Implants 2009;24(6):1083-92. 31. H ansson S. The implant neck: smooth or provided with retention elements. A biomechanical approach. Clin Oral Implants Res 1999;10(5):394-405. 32. Y ang B, Uchida M, Kim HM, Zhang X, Kokubo T. Preparation of bioactive titanium metal via anodic oxidation treatment. Biomaterials 2004;25(6):1003-10. 33. Ishikawa-Nagai S, Da Silva JD, Weber HP, Park SE. Optical phenomenon of periimplant soft tissue. Part II. Preferred implant neck color to improve soft tissue esthetics. Clin Oral Implants Res 2007;18(5):575-80. 34. Chen ST, Darby IB, Reynolds EC, Clement JG. Immediate implant placement postextraction without flap elevation. J Periodontol 2009;80(1):163-72.


35. Rimondini L, Fare S, Chiesa R, Pedeferri MP, Carrassi A. The effect of composition, wettability and roughness of the substrate on in vivo early bacterial colonization of titanium. J Appl Biomater Biomech 2003;1(2):131-8. 36. Del Curto B, Brunella MF, Giordano C, Pedeferri MP, Valtulina V, Visai L, et al. Decreased bacterial adhesion to surface-treated titanium. Int J Artif Organs 2005;28(7):718-30. 37. Zipprich H, Weigl P, Lange B, Lauer HC. Mircomovements at the Implant-Abutment Interface: Measurement, Causes, and Consequences Implantologie 2007;14(1):31-46. 38. Lazzara RJ, Porter SS. Platform switching: a new concept in implant dentistry for controlling postrestorative crestal bone levels. Int J Periodontics Restorative Dent 2006;26(1):9-17. 39. Polack MA. Restoration of maxillary incisors with a zirconia all-ceramic system: a case report. Quintessence Int 2006;37(5):375-80. 40. Jung RE, Holderegger C, Sailer I, Khraisat A, Suter A, Hammerle CH. The effect of all-ceramic and porcelain-fused-to-metal restorations on marginal periimplant soft tissue color: a randomized controlled clinical trial. Int J Periodontics Restorative Dent 2008;28(4):35765. 41. Mahn DH, Polack MA. Esthetic rehabilitation of maxillary incisors in conjunction with flapless surgical techniques, an implant zirconia crown, and porcelain veneers. J Esthet Restor Dent 2009;21(5):294-302. 42. Nguyen HQ, Tan KB, Nicholls JI. Load fatigue performance of implant-ceramic abutment combinations. Int J Oral Maxillofac Implants 2009;24(4):636-46. 43. Nakamura K, Kanno T, Milleding P, Ortengren U. Zirconia as a dental implant abutment material: a systematic review. Int J Prosthodont;23(4):299-309. 44. Mitsias ME, Silva NR, Pines M, Stappert C, Thompson VP. Reliability and fatigue damage modes of zirconia and titanium abutments. Int J Prosthodont;23(1):56-9. 45. Christensen GJ. Selecting the best abutment for a single implant. J Am Dent Assoc 2008;139(4):484-7. 46. van Brakel R, Noordmans HJ, Frenken J, de Roode R, de Wit GC, Cune MS. The effect of zirconia and titanium implant abutments on light reflection of the supporting soft tissues. Clin Oral Implants Res;22(10):1172-8. 47. Cook DR, Mealey BL, Verrett RG, Mills MP, Noujeim ME, Lasho DJ, et al. Relationship between clinical periodontal biotype and labial plate thickness: an in vivo study. Int J Periodontics Restorative Dent;31(4):345-54. 48. Zembic A, Sailer I, Jung RE, Hammerle CH. Randomized-controlled clinical trial of customized zirconia and titanium implant abutments for single-tooth implants in canine and posterior regions: 3-year results. Clin Oral Implants Res 2009;20(8):802-8. 49. Kelly JR, Nishimura I, Campbell SD. Ceramics in dentistry: historical roots and current perspectives. J Prosthet Dent 1996;75(1):1832. 50. Gallucci GO, Grutter L, Nedir R, Bischof M, Belser UC. Esthetic outcomes with porcelainfused-to-ceramic and all-ceramic single-implant crowns: a randomized clinical trial. Clin Oral Implants Res 2011;22(1):62-9.

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Sinus Lift Procedure in Presence of Mucosal Cyst:Wilcko et al A Clinical Prospective Study C. Maiorana1 • M. Beretta1 • M. Benigni1 • M. Cicciù2 • E. Stoffella1 • GB Grossi1

Abstract Background: Sinus lift procedures are considered safe and predictable procedures for the rehabilitation of the athrophic upper posterior maxilla. The presence of sinusal neoformation, highly reported in the literature, could represent a problem for sinus lifts. The removal of these lesions is recommended in order to limit intra- and post-operative complications. The aim of this prospective study is to describe the surgical removal of sinusal cyst concurrently with sinus lift procedures.

Results: All patients showed successful integration of the implants and the survival rate was 100% at the most recent recall. Intraoperative complications were rare and included minor membrane perforations in 3 cases. In 11 cases the CT scan examination revealed no sign of presence of the lesion after 6 months. In 3 cases the total volume of the lesion was significantly reduced. 4 patients presented thickening of the Scheiderian membrane up to 2 mm with no sign of inflammation.

Methods: 10 patients, 7 male and 3 female, presenting edentulism of the posterior maxilla associated with severe pneumatization of the maxillary sinus and presence of an antral cyst, were enrolled in the study. 14 sinus lift procedures were performed following aspiration of the liquid contained within the cyst. Radiographic exams were performed before, immediately after, and six months after the surgery.

Conclusions: This study proposes a modified surgical approach to drain the endoluminal liquid during the sinus lift procedure. The new proposed technique allows the reduction of the surgical morbidity thanks to the elimination of one surgical phase in case of staged approach. The Authors consider this technique safe and predictable.

KEY WORDS: Maxillary sinus lift, cyst, dental implant, bone augmentation 1. Department of Dental Implants, Fondazione IRCCS Cà Granda, University of Milan, Ospedale Maggiore Policlinico, Milan, Italy 2. Human Pathology Department, University of Messina University of Messina School of Dentistry


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Introduction Implant therapy in the posterior maxilla can be complicated by the qualitative and quantitative limitations of the residual bone, often interrelated with the pneumatization of the maxillary sinus.1 The sinus lift is a predictable surgical technique, strongly supported in the literature2,3 for many decades, providing a safe and stable base for endosseous implant placement.4 Some authors have stated that the presence of an antral cyst would be a contraindication for the predictability of the sinus lift procedure in these particular patients5 while other studies assess that pseudocysts do not affect the possibility to perform a sinus grafting procedure.6 The aim of this prospective study is to evaluate, by means of clinical and radiological examination (CT scan), the effectiveness of a modified sinus lift procedure in case of severe pneumatization of the maxillar sinus associated with presence of antral cyst.

Materials and methods Patients 10 patients, 7 male and 3 female, presenting edentulism of the posterior maxilla associated with severe pneumatization of the maxillary sinus and presence of an antral cyst, were enrolled in the study. Fourteen sinus lift procedures were performed. The group had a mean age of 45.3 years, ranging from 27 to 73 years. Demographic data, medical and dental health history and smoking habits were registered. General inclusion criteria for oral surgery procedures were considered. Patients were excluded from the study if they had a medical history of any systemic disease that would impair wound healing, such as non-controlled diabetes mellitus, immunosuppressive drugs and heavy smok-

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ing (more than 10 cigarettes per day). Each patient received a comprehensive dental examination and a periodontal chart was filled, in order to determine the periodontal and dental status. Radiographic examination included Panoramic exam, coronal and axial CT scans. Assessment of maxillary sinus anatomy, vertical dimension of the sinus floor and an evaluation of any pathologic findings were carried out on each patient. All patients with a radiographic finding of a dome-shaped radiopacity compatible with an antral pseudocyst were included in the study (Figures 1-3). Patients with a lesion less than 1 cm² with diffuse mucosal thickening or irregular calcifications were excluded. Criteria for sinus augmentation were a maxillary vertical dimension of less than 8 mm with al least 1 mm of residual bone height. All patients were referred to a otorhinolaryngologist in order to perform sinus examination and an endoscopic procedure (FESS) when required. The endoscopic and radiographic examination (CT scan) by the otorhinolaryngologist had the aim to exclude pathological conditions such as: chronic sinusitis with retention of mucous secretions in the sinus, ostium stenosis or obstruction, presence of bony destruction and communication with dental roots. All subjects were informed regarding the treatment sequence and the procedures involved and were provided a signed informed consent. Surgical Procedure Sinus augmentation was performed following the guidelines stressed by Tatum.3 After antibiotic prophylaxis by means of 2 grams of amoxicillin 1 hour before the surgery, anesthesia was obtained by local infiltration of Ecocain 1:50,000 and 4 mg of dexamethasone were infiltrated locally. A crestal

Maiorana et al

Figure 1: Panoramic exams showing a neoformation on the floor of the maxillary sinus.

Figure 2: Panoramic exams showing a neoformation on the floor of the maxillary sinus.

incision slightly palatal to the crest in order to preserve a band of keratinized attached mucosa and two vertical release incisions were carried out to reflect a mucoperiosteal flap. The lateral wall of the maxillary sinus was exposed and an osteotomic window was performed using a round bur7 (Figure 4). A perforation through the vestibular wall of the maxillary sinus was made 5 mm over the upper side of the bony window using a 2 mm round bur (Figure 5). This procedure was performed to allow a direct access to the mucosal cyst in order to suck out the liquid contained in the neoformation by means of a syringe inserted into this communication (Figure 6). The liquid extraction consented to reduce the internal pressure of the cyst, thus diminishing the dimension of the lesion and the risk of laceration during the lifting of the scheiderian membrane. The sinus membrane was then gently lifted from the bony floor by means of an antral curette. The created sub-antral cavity was then grafted with anorganic bovine bone (Bio-oss Geistlich, Wolhusen, CH) (Figure 7). In 9 procedures the vertical residual bone height was sufficient to allow the primary stability of implants inserted at the same time of the sinus lift procedure. In 5 procedures a staged procedure

Figure 3: CT scan exam shows the presence of a neoformation in the right maxillary sinus.


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Figure 4: Crestal incision with two vertical release and exposure of the lateral wall of the maxillary sinus.

Figure 5: A perforation was made 5 mm above the upper side of the bony window to allow the suction of the liquid inside the cyst.

Figure 6: Enucleation of the cyst.

Figure 7: The sinus wall was grafted with anorganic bovine bone. (Bio-oss Geistlich, Wolhusen, CH).

with delayed implant placement because of the insufficient residual bone was performed. Thirty four implants were placed, 25 in single procedure and 9 in staged approach. The graft material was covered by a resorbable collagen membrane (Biogide Geistlich, Wolhusen, CH) and a primary closure wound healing was obtained with a 4-0 non resorbable suture (Figure 8). Post-operative management included systemic antibiotics (1 gram Amoxicillin 3 times a

day for 7 days), application of decongestant nasal spray, chlorohexidine 0.20% mouthwash (3 times a day for 15 days) and analgesic. Patients were instructed to avoid use of any removable appliance for the first 2 weeks postoperatively.

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Clinical and Radiographic Follow-Up The patients were seen once a week for the first post-op month, and then once a month for the following 5 months. Suture removal was

Maiorana et al

Figure 8: The graft material was covered by a resorbable collagen membrane. (Biogide Geistlich, Wolhusen, CH).

FIgure 9: in 3 cases a laceration of the schneiderian membrane occurred.

Figure 10: Panoramic exam shows implant integration in the right and left maxillary sinus.

performed 15 days post-operatively. Radiographic examinations were made at the time of surgery (panoramic exam) and after 6 months (panoramic exam and CT scan). Figure 11: Cross sections show good implants integration in the sinus graft 6 months after the surgery.

Results Mean follow-up was 12 to 40 months. All cessful integration of vival rate was 100%

28 months the patients the implants at the most

ranging from showed sucand the surrecent recall.


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Intraoperative complications were rare and included minor membrane perforations in 3 cases. The lacerations were in an area where the membrane was thin and far from the perforation created to drain the liquid from the cyst (Figure 9). No complications, such as infection of the grafted material or acute sinusitis were registered during the postoperatively period and during the follow-up recall in all the surgical sites. Six month radiologic follow-up (CT scan) showed good integration of the grafting material in all the patients (Figures 10, 11). In 11 cases the CT scan examination revealed no sign of presence of the lesion after 6 months. In 3 cases the total volume of the lesion was significantly reduced. Four patients presented thickening of the Scheiderian membrane up to 2 mm with no sign of inflammation.

Discussion The presence of cyst-like opacity in the maxillary sinus is commonly asymptomatic and diagnosed on routine radiographic examination taken for other reasons, such as dental rehabilitation, impacted teeth, or to assess the alveolar ridge for implant rehabilitation. The literature reported two different values of antral cyst prevalence depending on the type of radiological examinations: between 1.4% and 9.6% in case of Panoramic exam9 and 12.4% in case of CT scan.10 Sinus augmentation is associated with several complications, with postoperative sinusitis and bone graft infection as the most serious. The development of sinusitis following sinus augmentation can be directly related to drainage disturbances, mainly as a result of septal deviation and allergy, combined with oversized inferior and middle turbinates. The presence of

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antral pseudocyst reduces the size of the maxillary antrum. Therefore, it can be speculated that lifting the maxillary mucosal lining in this case would further reduce the sinus size and postoperative edema of the Schneiderian membrane. The ostium opening may be blocked causing stasis of fluids, which when contaminated, could lead to sinusitis. Nevertheless, because of the high position of the ostium relative to the sinus floor, especially in a large antrum, the reported prevalence of sinusitis following sinus augmentation in the absence of any pathology is about 3% to 20% of the cases reported in the literature11-13 Differential diagnosis of an antral pseudocyst from other sinus lesions is crucial for treatment planning. As the maxillary sinuses may become involved with several types of diseases, including chronic rhinosinusitis, benign and malignant neoplasms, or even dental disorders, appropriate diagnosis is mandatory prior to any intervention.14,15 In particular radiological evaluation (Panoramic exam and CT scan) and ENT examination with endoscopic approach are necessary to determine benign or malignant nature of the lesion.16 Ostium stenosis has been strongly associated with chronic maxillary sinusitis and nasal polyps/cysts.17 The risk of ostium stenosis is highly augmented in case of sinus lift procedure in presence of antral cyst which can lead to the iatrogenic closure of the nasal meatus during the surgical procedure.18 The patency of the sinonasal ostium is fundamental to guarantee the possibility for the sinus to drain the physiological mucus thanks to the mucociliar flux reducing the risk of sinusitits. In particular the sinus lift procedure leads to a major quantity of mucus to be drained, due to the surgical insult or an eventual migration of

Maiorana et al

the grafting material in the antral cavity in case of perforation of the Schneiderian membrane.19 The literature suggests a surgical-endoscopic approach to remove the intrasinusal lesion, in order to consent the possibility to perform the sinus lift procedure and the implant insertion.20, 21

Conclusion The Authors propose a modified surgical approach to drain the endoluminal liquid during the sinus lift procedure. The new proposed technique allows the reduction of the surgical morbidity thanks to the elimination of one surgical phase in case of staged approach. Furthermore, a pseudocyst of the maxillary sinus is not a contraindication for sinus augmentation. The low frequency of sinus membrane perforation and postsurgical sinusitis makes the operation safe.6 Nevertheless, in patients with large lesions and where the diagnosis is not clear, further evaluation should be made before sinus augmentation is scheduled. It is mandatory for the surgeon to be familiar with the anatomy and pathology of the maxillary sinus to avoid any unnecessary complications. For this reason, pre - surgical radiographic evaluation of the maxillary sinus by a trained surgeon is mandatory to avoid unnecessary complications. Most cases of antral pseudocyst are directly related to the severity of periodontal disease and odontogenic infections. ● Correspondence: Dr. Carlo Maiorana Clinica Odontostomatologica, Ospedale Maggiore Policlinico, Via della Commenda n. 10 20132 Milano, Italy Phone: 0039335602527; Email: [email protected]


ATTENTION PROSPECTIVE AUTHORS JIACD wants to publish your article! For complete details regarding publication in JIACD, please refer to our author guidelines at the following link: http://www.jiacd.com/ authorinfo/ author-guidelines.pdf or email us at: [email protected]


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Disclosure The authors report no conflicts of interest with anything mentioned in this article. References 1. Naert I, Koutsikakis G, Duyck J, Quirynen M, Jacobs R, van Steenberghe D. ;Biologic outcome of implant-supported restorations in the treatment of partial edentulism. Part I: A longitudinal clinical evaluation. Clin Oral Implants Res 2002; 13(4):381-389. 2. B oyne PJ, James RA ; Grafting of the maxillary sinus floor with autogenous marrow and bone. J Oral Surg 1980; 38(8):613-6. 3. T atum H Jr; Maxillary reconstructions. Dent 1986;30(2):207-29.

and sinus implant Clin North Am

4. 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. 5. Ziccardi and Betts Quintessence 1999 ardinger O, Manor I, Mijiritsky E, Hirshberg A; 6. M Maxillary sinus augmentation in the presence of antral pseudocyst: a clinical approach. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2007;103(2):180-184. oo I, Le BT; Maxillary sinus floor elevation: 7. W review of anatomy and two techniques. Implant Dent 2004; 13(1):28-32. 8. W allace 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 window: histomorphometric and clinical analyses. Int J Periodontics Restorative Dent. 2005 Dec;25(6):551-559 acDonald-Jankowski DS. Mucosal antral cysts 9. M observed within a London inner-city population. Clin Radiol 1994;49:195-198. 10. B hattacharyyan N. Do maxillary sinus retention cysts reflect obstructive sinus phenomena? Arch Otolaryngal Head Neck Surg 2000;126:1369-1371. iltfang J, Schultze-Mosgau S, Merten HA, 11. W Kessler P, Ludwig A, Engelke W; Endoscopic and ultrasonographic evaluation of the maxillary sinus after combined sinus floor augmentation and implant insertion; Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2000;89:2882-91

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12. T immenga NM, Raghoebar GM, Boering G, Van Weissenbruch R; Maxillary sinus function after sinus lifts for the insertion of dental implants. J Oral Maxillofac Surg 1997;55:936939.

24. G arg AK, Mugnolo GM, Sasken H; Maxillary antral mucocele and its relevance for maxillary sinus augmentation grafting: a case report. Int J Oral Maxillofac Implants 2000; 15(2):287290.

arg AK, Mugnolo GM, Sasken H. Maxillary 13. G antral mucocele and its relevance for maxillary sinus augmentation grafting: a case report. Int J Oral Maxillofac Implants 2000;15:287-290.

25. T hio D, Phelps PD, Bath AP; Maxillary sinus mucocele presenting as a late complication of a maxillary advancement procedure. J Laryngol Otol. 2003 May;117(5):402-3.

iecidue RJ, Streck PD, Spera JF. Diagnosis 14. D of benign lesions of the maxillary sinus. Oral Maxillofac Surg Clin N Am 1999;11:83-100.

arg AK; Augmentation grafting of the 26. G maxillary sinus for placement of dental implants: anatomy, physiology, and procedures. Implant Dent 1999;8(1):36-46.

ciubba JJ. Diagnosis of malignant tumors of 15. S the maxillary sinus. Oral Maxillofac Clin N Am 1999;11:117-123. 16. B eaumont C, Zafiropoulos GG, Rohmann K, Tatakis DN; Prevalence of maxillary sinus disease and sbnormalities in patients sceduled for sinus lift procedures. J Periodontol 2005;76:461-467. ilbert JG. Antroscopy in maxillary sinus 17. G disease associated with nasal polyposis. J Laryngol Otol 1989;103:861-863. 18. E arwaker J. Anatomic variants in sinonasal CT. Radiographics 1993;13:381-415. 19. B achert C, Ganzer U. Experimental studies on the relationship between maxillary sinus ventilation and various obstructions of the moise and the nasopharynx. Rhinology 1989;27:37-43. raf W. Endonasal surgery of the paranasal 20. D sinuses. HNO Praxis H Eute. 1992;12:59-80. 21. S tammberger H, Posawetz W. Functional endoscopic sinus surgery. Concept, indications and results of the Messerklinger technique. Eur Arch Otorhinilaryngol 1990;247:63-76.

27. C aylakli F, Yavuz H, Cagici AC, Ozluoglu LN; Endoscopic sinus surgery for maxillary sinus mucoceles. Head Face Med 2006; 6:29. 28. B usaba NY, Salman SD; Maxillary sinus mucoceles: clinical presentation and longterm results of endoscopic surgical treatment. Laryngoscope 1999; 109(9):1446-1449. avioli C, Grasso DL, Carinci F, Amoroso C, 29. G Pastore A; Mucoceles of the frontal sinus. Clinical and therapeutical considerations. Minerva Stomatol 2002; 51(9):385-390. 30. N audo P, Gilain L, Coste A, Lelièvre G, Peynegre R; Functional endoscopic surgery of sinusal mucocele. Ann Otolaryngol Chir Cervicofac 1994;111(1):23-27. 31. K im HY, Dhong HJ, Min JY, Jung YG, Park SH, Chung SK; Postoperative maxillary sinus mucocoele: risk factors for restenosis after surgery and preventive effects of mytomycin-C. Rhinology 2009; 47(1):79-88. eer S, Altini M; Cysts and pseudocysts of 32. M the maxillary antrum revisited. SADJ 2006; 61(1):10-13.

abibi A, Sedaghat MR, Habibi M, Mellati E; 22. H Silent sinus syndrome: report of a case. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2008; 105(3):e32-35.

33. V eltrini V, Ferreira Júnior O, Oliveira DT; Mucosal cysts of the maxillary sinus: a literature review. Med Oral 2001; 6(3):180188.

erfetti G, Rossi F, Massei G, Raffaelli L, 23. P Manicone PF, Paolantonio M, Berardi D, Neri G; Sinus augmentation procedure of the jaw sinus in patients with mucocele. Int J Immunopathol Pharmacol 2008; 21(1):243246.

eissman JL, Curtin HD, Eibling DE; Double 34. W mucocele of the paranasal sinuses. AJNR Am J Neuroradiol 1994; 15(7):1263.


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Influence of the Crown-To-Implant Ratio on Crestal Bone Loss

Wilcko et al

Oswaldo Andreé Cáceres La Torre, DDS, MSc1 Jorge Noriega Castañeda DDS, MSc1 • Miguel Angel Coz Fano DDS, MSc2 Abstract

Purpose: Previous research suggests that the crown-to-root ratio considerations associated with natural teeth should not be applied in implant restorations. The aim of this prospective study was to determine the influence of the crown-to-implant ratio on crestal bone loss for dental implant restorations. Material and Methods: Clinical and radiographic assessments were performed at baseline and 12 months later for restored dental implants. In order to determine the peri-implant crestal bone loss, we used a standardized periapical technique. Results: Seventy-eight implants were evaluated on a total of 31 patients. Single and splinted crowns were included in the study.

The total number of implants was divided into five groups according to their crown-to-implant ratio: 0 to 0.99, 1 to 1.19, 1.2 to 1.39, 1.4 to 1.59, and ≥ 1.6. The mean of the crestal bone loss of these groups was 0.22mm, 0.16mm, 0.36mm, 0.19mm and 0.52mm respectively. The difference among these groups was statistically significant (p 0.01). The mean of the crestal bone loss for the total of evaluated implants was 0.15mm after 12 months; and the mean of the crown-to-implant ratio was 1.46. Conclusion: The crown-to-implant ratio influences the peri-implant crestal bone loss during a follow-up period of 12 months; these results suggested that a higher crown-toimplant ratio increases the crestal bone loss.

KEY WORDS: Dental implant, peri-implant bone loss, crown-to-implant ratio 1. Assistant Professor, Master of Periodontology, Universidad de San Martín de Porres, Perú. 2. Professor, Head and Chairman, Master of Periodontology, Universidad de San Martín de Porres, Perú.


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Cáceres La Torre et al

INTRODUCTION Earlier follow-up studies of dental implants were intended to demonstrate their long-term success. In these studies, the crestal bone loss was considered an important criterion for determining the success of the implants.1 2 3 It has been established that bone loss should not be greater than one third of the length of the implant4 or, as proposed by Albrektsson et al.5, that the annual bone loss should not exceed 0.2 mm after the first year of placement. There are several imaging techniques that allow us to identify the peri-implant bone loss. However, the standardized periapical technique has demonstrated a high positive predictive value for the radiographic diagnosis of implant stability.6 It has also been suggested that the standardized periapical technique is reliable for performing longitudinal measurements in comparison to the panoramic radiography, conventional tomography and computerized tomography.7 Most recent studies have focused on minimizing bone loss, and take into account biomechanical aspects to prevent overloading. One of these biomechanical aspects is guiding the direction of the forces towards the long axis of the implant body to reduce the magnitude of the forces.8 9 The literature suggests that in order to reduce the magnitude of mechanical stresses acting on the implant-bone interface, the area of the implants should be increased with implants of greater length or diameter.10 Thus, the crownto-implant ratio should be considered when planning an implant-supported restoration. However, the crown-to-implant ratio is a variable poorly studied in terms of its relation to crestal bone loss. It has been previously reported that, restorations with a crown-to-implant ratio from 1.1 to 2.0 do not affect the crestal bone level11 and the

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increase of the crown-to-implant ratio does not represent a major risk factor in cases with favorable loads.12 Blanes et al.13 reported cases with a crown-to-implant ratio of 2 to 3 being successful. Schulte et al.14 observed that the crown-to-implant ratio of implants which remained in function was similar to those that failed. They suggest that the crown-to-root ratio considerations associated with natural teeth should not be applied in implant restorations. The aim of this study was to determine the influence of the crown-to-implant ratio on crestal bone loss in patients treated at the Clinic of Periodontics at the School of Dentistry, Universidad de San Martín de Porres.

MATERIALS AND METHODS Population During the period from January 2001 to August 2008, a total of 350 Lifecore dental implants (Lifecore Biomedical®, Chaska, Minnesota, USA) were placed in 145 patients treated at the Clinic of Periodontics at the School of Dentistry, Universidad San Martín de Porres in Lima, Perú. The population of the study comprised all patients with implants restored with either single or splinted crowns, which comprised 144 implants placed in 59 patients. We worked with a non-probabilistic sample which consisted of all patients who were able to be located and attended to their dental evaluations. Inclusion Criteria ● Osseointegrated implants which were restored with either single or splinted crowns ●R BM® (Resorbable Blasted Media) textured surface implants ● Implants from patients who came to the monitoring and agreed to participate in the study through an informed consent

Cáceres La Torre et al

Figure 1a: Baseline clinical evaluation of dental implant.

● Implants placed in systemically stable and/or compensated patients ● Functionally stable implants (no pain, no mobility and no suppuration) Exclusion Criteria ● Medical records with incomplete patient or treatment information ● Implants placed in patients with a history of smoking ● Implants placed in patients with parafunctional habits ● Immediate and early loaded implants

Data Collection Analysis of Documents The information about patients was obtained through the documentary analysis of the surgical record book, medical history, and records. The information included the surgical procedure and the prosthetic restoration.

Figure 1b: Baseline radiographic evaluation of dental implant.

Clinical Evaluation The patients attended to the Clinic of Periodontics, Universidad San Martin de Porres for an initial clinical and radiographic evaluation. A second evaluation was performed 12 months after the initial evaluation (Figures 1a, 1b). First, a clinical evaluation was performed to determine the stability of the implants. Lack of mobility, presence of pain and infection attributable to the implant were considered. All implants that were evaluated received periodontal maintenance therapy in order to obtain and maintain a good oral hygiene index during the follow-up period (O’Leary index