Titanium Mesh Ridge Augmentation for Dental Implant Placement · Implant Placement: A Case Report...

The Journal of Implant & Advanced Clinical Dentistry

Volume 8, No. 3 may/JuNe 2016

Treatment of Mandibular Central Giant Cell Granuloma

Titanium Mesh Ridge Augmentation for Dental

Implant Placement

Get Social with

@JIACD on twitter

“JIACD dental journal” on LinkedIn

JIACD on FB

Scan With YourSmartphone!

In order to scan QR codes,your mobile device

must have a QR codereader installed.

Wan

t Reg

ener

ative

Trea

tmen

t Sol

utio

ns?

Try A

n Oss

eoGua

rd® M

embr

ane

And

Endo

bon

® Xeno

graf

t

Granu

les!

OsseoGuard® Membranes And Endobon® Xenograft Granules Provide Clinicians One Solution At A Time

Protect Sites For Consistent Results During

Grafting Procedures

Choose Between Two Levels Of Drapability For Ease Of Use In

Various Clinical Scenarios

Slow Resorption ForBone Volume Retention

Conveniently PackagedIn NEW Value Packs

For More InformationAbout BIOMET 3iRegenerative Treatment Solutions, Contact YourLocal Sales Representative Today! In the USA: 1-888-800-8045, Outside The USA: +1-561-776-6700 Or Visit Us Online At www.biomet3i.com

Endobon, OsseoGuard and RegenerOss are registered trademarks of BIOMET 3i LLC.OsseoGuard Flex and Providing Solutions - One Patient At A Time are trademarks ofBIOMET 3i LLC. ©2011 BIOMET 3i LLC.

ClinicallyManageable

Value Packs

Bone Volume

MaintenancePredictable

INTRODUCING

Join Us

Follow Us

Watch Us

DownloadIt

Regenerative Treatment Solutions

NEWPACKAGING

NEWOsseoGuard Flex™

Membrane

OsseoGuard® Membrane And The NEW OsseoGuard Flex™ Membrane

Endobon® Xenograft GranulesWith NEW Packaging

JIACD_Jan2012_BIOMET 3i 12/16/11 5:10 PM Page 1

The Journal of Implant & Advanced Clinical Dentistry • 3

The Journal of Implant & Advanced Clinical DentistryVolume 8, No. 3 • may/JuNe 2016

Table of Contents

11 Localized Ridge Augmentation using Titanium Mesh with Alloplast and Simultaneous Implant Placement: A Case Report Dr. Lanka Mahesh, Dr. Dildeep Bali, Dr. Vishal Gupta, Dr. Taran Preet Singh

21 Treatment of a Central Giant Cell Granuloma of the Mandible Robert Schneider, Steven L. Fletcher, Kyle M. Stein

31 The Effects of Reinforcement on the Fracture Rates of Provisional All-On-4 Restorations: A Retrospective Report of 257 Cases Involving 1182 Dental Implants Dr. Dan Holtzclaw

www.sybronimplants.com

The SybronPRO™ Series Implant System designed to provide immediate stability1, preservation of crestal bone2, and long-term aesthetics... from a name you can trust.

Sybron - Celebrating over 100 years of dental excellence.

For more information, contact Sybron Implant Solutions today.

SURGICAL FLEXIBILITY. PROSTHETIC VERSATILITY.SYBRON DEPENDABILITY.

HEADQUARTERSUSA1717 West Collins AveOrange, California 92867 T 714.516.7800

EuropeJulius-Bamberger-Str. 8a28279 Bremen, GermanyT 49.421.43939.0

United Kingdom4 Flag Business ExchangeVicarage Farm RdPeterborough, UK PE1 5TXT 00.8000.841.2131

France16 Rue du Sergent Bobillot93100 Montreuil, FranceT 33.149.88.60.85

Australia# 10, 112-118 Talavera RdNorth Ryde, NSW 2113T 61.2.8870.3099



Table of Contents

39 Effect of Root Support versus Implant Support on the Biting Force of Attachment Retained Mandibular Overdentures Dr. Maha W. Elkerdawy, Dr. Nancy N. Elsherbini

47 Comparative Analysis of User Generated Online Yelp Reviews for Periodontal Practices in Multiple Metropolitan Markets Dr. Dan Holtzclaw

59 Analysis of Online Review Characteristics and Filtering Rates for User Generated Yelp Evaluations of Periodontal Practices in a Major Metropolitan Market Dr. Dan Holtzclaw



PublisherLC Publications

DesignJimmydog Design Group www.jimmydog.com

Production ManagerStephanie Belcher 336-201-7475 • [email protected]

Copy EditorJIACD staff

Digital ConversionJIACD staff

Internet ManagementInfoSwell 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 © 2016 by LC Publications. 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 LC Publications (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 JIACD-SOM. 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 LC Publications, Las Vegas, Nevada, USA.


Tara Aghaloo, DDS, MDFaizan Alawi, DDSMichael Apa, DDSAlan M. Atlas, DMDCharles Babbush, DMD, MSThomas Balshi, DDSBarry Bartee, DDS, MDLorin Berland, DDSPeter Bertrand, DDSMichael Block, DMDChris Bonacci, DDS, MDHugo Bonilla, DDS, MSGary F. Bouloux, MD, DDSRonald Brown, DDS, MSBobby Butler, DDSNicholas Caplanis, DMD, MSDaniele Cardaropoli, DDSGiuseppe Cardaropoli DDS, PhDJohn Cavallaro, DDSJennifer Cha, DMD, MSLeon Chen, DMD, MSStepehn Chu, DMD, MSD David Clark, DDSCharles Cobb, DDS, PhDSpyridon Condos, DDSSally Cram, DDSTomell DeBose, DDSMassimo Del Fabbro, PhDDouglas Deporter, DDS, PhDAlex Ehrlich, DDS, MSNicolas Elian, DDSPaul Fugazzotto, DDSDavid Garber, DMDArun K. Garg, DMDRonald Goldstein, DDSDavid Guichet, DDSKenneth Hamlett, DDSIstvan Hargitai, DDS, MS

Michael Herndon, DDSRobert Horowitz, DDSMichael Huber, DDSRichard Hughes, DDSMiguel Angel Iglesia, DDSMian Iqbal, DMD, MSJames Jacobs, DMDZiad N. Jalbout, DDSJohn Johnson, DDS, MSSascha Jovanovic, DDS, MSJohn Kois, DMD, MSDJack T Krauser, DMDGregori Kurtzman, DDSBurton Langer, DMDAldo Leopardi, DDS, MSEdward Lowe, DMDMiles Madison, DDSLanka Mahesh, BDSCarlo Maiorana, MD, DDSJay Malmquist, DMDLouis Mandel, DDSMichael Martin, DDS, PhDZiv Mazor, DMDDale Miles, DDS, MSRobert Miller, DDSJohn Minichetti, DMDUwe Mohr, MDTDwight Moss, DMD, MSPeter K. Moy, DMDMel Mupparapu, DMDRoss Nash, DDSGregory Naylor, DDSMarcel Noujeim, DDS, MSSammy Noumbissi, DDS, MSCharles Orth, DDSAdriano Piattelli, MD, DDSMichael Pikos, DDSGeorge Priest, DMDGiulio Rasperini, DDS

Michele Ravenel, DMD, MSTerry Rees, DDSLaurence Rifkin, DDSGeorgios E. Romanos, DDS, PhDPaul Rosen, DMD, MSJoel Rosenlicht, DMDLarry Rosenthal, DDSSteven Roser, DMD, MDSalvatore Ruggiero, DMD, MDHenry Salama, DMDMaurice Salama, DMDAnthony Sclar, DMDFrank Setzer, DDSMaurizio Silvestri, DDS, MDDennis Smiler, DDS, MScDDong-Seok Sohn, DDS, PhDMuna Soltan, DDSMichael Sonick, DMDAhmad Soolari, DMDNeil L. Starr, DDSEric Stoopler, DMDScott Synnott, DMDHaim Tal, DMD, PhDGregory Tarantola, DDSDennis Tarnow, DDSGeza Terezhalmy, DDS, MATiziano Testori, MD, DDSMichael Tischler, DDSTolga Tozum, DDS, PhDLeonardo Trombelli, DDS, PhDIlser Turkyilmaz, DDS, PhDDean Vafiadis, DDSEmil Verban, DDSHom-Lay Wang, DDS, PhDBenjamin O. Watkins, III, DDSAlan Winter, DDSGlenn Wolfinger, DDSRichard K. Yoon, DDS

Editorial Advisory Board

Founder, Co-Editor in ChiefDan Holtzclaw, DDS, MS

Co-Editor in ChiefLeon Chen, DMD, MS, DICOI, DADIA

The Journal of Implant & Advanced Clinical Dentistry

Mahesh et al

Autoclavable LED's Progressive Pedal Controlled Power

- Three times more power than PIEZOTOME1! (60 watts vs 18 watts of output power in the handpiece) Procedures are faster than ever, giving you a clean and effortless cut- NEWTRON LED and PIEZOTOME2 LED Handpieces output 100,000 LUX!- Extremely precise irrigation flow to avoid any risk of bone necrosis- Selective cut: respect of soft tissue (nerves, membranes, arteries) - Less traumatic treatment: reduces bone loss and less bleeding- 1st EVER Autoclavable LED Surgical Ultrasonic Handpieces - Giant user-friendly 5.7" color touch-control screen - Ultra-sharp, robust and resistant tips (30+ Surgical & 80+ Conventional)

PIEZOTOME2 and IMPLANT CENTER2

- I-Surge Implant Motor (Contra-Angles not included)- Compatible with all electric contra-angles (any ratio)- Highest torque of any micro-motor on the market- Widest speed range on the market

All the benefits of the PIEZOTOME2...PLUS...

ACTEON North America 124 Gaither Drive, Suite 140 Mount Laurel, NJ 08054Tel - (800) 289 6367 Fax - (856) 222 4726

www.us.acteongroup.com E-mail: [email protected]

..

.

Mahesh et al

Implant placement in the atrophic anterior part of the maxilla was once a difficult task. Many pro-cedures have been developed over the years

for reconstruction of the alveolar ridge to enable implant placement. Alveolar ridge augmentation along with guided bone regeneration has been introduced in recent years to re-establish an appro-priate alveolar ridge width. In guided bone regen-eration, the quantity of bone regenerated under the membranes has been demonstrated to be directly related to the amount of the space under the mem-

branes. This space can diminish as a result of membrane collapse. To avoid this problem, a new technique of ridge augmentation, which involves the use of a titanium mesh barrier to protect the regen-erating tissues and to achieve a rigid fixation of the bone segments is been used. In this case, excel-lent results can be seen in which maxillary anterior defect is augmented using guided bone regen-eration with simultaneous placement of implant at the site 11 (FDI Tooth Numbering System) using alloplast graft material protected by titanium mesh.

Localized Ridge Augmentation using Titanium Mesh with Alloplast and Simultaneous

Implant Placement: A Case Report

Dr. Lanka Mahesh1 • Dr. Dildeep Bali2 Dr. Vishal Gupta1 • Dr. Taran Preet Singh1

Abstract

KEY WORDS: Oral tumors, dental implants, CAD/CAM frameworks, partial mandibulectomy, central giant cell granuloma, grafting


1. Private Practice, New Delhi, India

2. Professor, Department of Endodontics, Santosh Dental College, UP India

12 • Vol. 8, No. 3 • May/June 2016

INTRODUCTIONResorption of the edentulous or partially edentu-lous alveolar ridge or bone loss due to periodon-titis or trauma frequently compromises dental implant placement in a prosthetically ideal position. Therefore, augmentation of an insufficient bone volume is often indicated prior to or in conjunc-tion with implant placement to attain predictable long-term functioning and an esthetic treatment outcome.1 These deformities can lead to compli-cations in attempts for the restoration of related areas. In recent years there has been an increase in the number of studies focusing on the augmen-tation of these atrophic ridges either before or at the time of implant surgery.2-6 Predictable bone regeneration of large alveolar defects with com-plex morphology can pose a significant clinical challenge. Preservation or creation of a soft tissue scaffold needed to create the illusion of a natural tooth is often challenging and difficult to achieve.7 A subtle mistake in the positioning of the implant or the mishandling of soft or hard tissue can lead to esthetic failure and patient dissatisfaction.8-10

Autogenous bone grafts are still considered the gold standard in bone regeneration proce-dures.11 However, donor site morbidity, unpredict-able resorption, limited quantities available, and the need to include additional surgical sites are drawbacks related to autografts that have intensi-fied the search for suitable alternatives. Bone-sub-stitute materials have increased in popularity as adjuncts to or replacements for autografts in bone augmentation procedures to overcome the limita-tions related to the use of autografts. Bone-substi-tute materials can be categorized in three groups: (1) allogenic, from another indi-vidual within the same species; (2) xenogeneic, from another species;

or (3) alloplastic, synthetically produced.The technique of guided bone regeneration

(GBR) was evolved to augment atrophic or dam-aged ridges.11 GBR employs a physical barrier to selectively allow new bone growth into the space created between the barrier and the existing bone.12 The emergence of synthetic bone substitutes for grafting should enable today’s practitioners to perform an almost endless variety of procedures that involve the repair or regeneration of alveolar bone around dental implants or natural teeth. Such materials must satisfy various regulatory require-ments and meet clinicians expectations for safety and effectiveness.13 It has been shown that an expanded polytetrafluoroethylene membrane can be used to improve the healing of both pathologic and experimentally created defects.14 The rationale of using a titanium mesh is to contain and stabi-lize the graft, allowing maximum bone regeneration and minimizing overall loss of bone volume. Vari-ous forms of titanium mesh have been success-fully used to rigidly maintain the alveolar contour with different types of grafts. Graft materials such as alloplast in combination with membranes enhance success of the treatment of bone defects.

CASE REPORTA 19-year-old male reported with missing maxil-lary right central incisor. The patient gave history of trauma due to accident which resulted in loss of maxillary right central incisor. On clinical exam-ination, deficiency in the anterior residual alveo-lar ridge with loss of buccal cortical plate was noted. The patient was in good health and was a non-smoker with no medical contraindications for surgery, with excellent oral hygiene and a strong desire to restore the area with a fixed prosthesis. On examination there were no clinical signs of

Mahesh et al


periodontitis and dental caries. Radiographically the clinical findings were verified and revealed vertical and horizontal bone loss that was lim-ited to the maxillary right central incisor (Fig 1).

TREATMENT PLANNINGThe patient was presented with different treat-ment options, after discussing the pros and cons of each the following treatment option was planned to receive an implant supported crown restoration after augmentation of the com-promised alveolar ridge in the area of missing

tooth 11 using alloplast bone graft secured with titanium membrane. Fixed partial denture was planned for replacing mandibular central incisors because of patient’s economic problems. None-theless, he gave informed consent for the same.

TREATMENT PROCEDUREA local anesthetic was administered in the area of the maxillary right upper central incisor. An incision was made on the buccal and palatal aspect of the involved edentulous ridge and a full thickness flap was reflected from tooth 12

Figure 1: CBCT showing the vertical bone loss and deficient labial cortical bone in relation to tooth 11 (FDI tooth numbering system).

Figure 2: Bone defect.

Figure 3: Surgical placement of dental implant.

Mahesh et al

14 • Vol. 8, No. 3 • May/June 2016

Mahesh et al

to tooth 21 and bone defect was found defi-cient both horizontally and vertically (Fig. 2). The Osteotomy was created under copious irrigation on surgical site. A Kelt implant of 3.8x11.5mm (Bioner, Barcelona, Spain) was inserted at 35 Ncm (Fig. 3). Approximately 1 cc of calcium phosphosilicate (CPS) alloplast morsels (Nova-Bone, Alachua, FL, USA) (Fig. 4) was mixed with sterile saline and allowed to hydrate before being placed and packed into the defect and positioned to fill all void areas. A titanium mesh (Fig. 5) was trimmed to size and placed under the facial flap following the GBR protocol to secure the bone graft in its place and was fixated with the cover screw of the implant. Extensive periosteal releas-ing incisions were made in the facial flap and per-mit complete coverage of the membrane. Primary wound closure was obtained by horizontal mat-tress and interrupted polytetrafluorethylene (PTFE) 4-0 sutures (Osteogenics Lubbock, Texas, USA). Oral hygiene instructions were given to the patient.

The patient was seen post surgically after two weeks for suture removal and no untoward post-

operative symptoms were noted. The patient was put on a two week, one month, three month and six month recall ensuring the proper management of implant site. An interim fixed Maryland bridge was resin bonded during the healing phase. After 5 months, prior to second stage surgery a cone-beam computed tomography (Fig. 6) was performed and a horizontal bone gain of 5.3 mm was noted (Fig 7). The patient was recalled for second stage surgery where the titanium membrane was removed and the healing collar placed (Fig. 8). Following three weeks, upper and lower impressions were made with Imp-regum (3M ESPE, St. Paul, Minnesota, USA). The final prosthesis was then delivered (Fig. 9). The radiographic image after final prosthesis (Fig. 10).

DISCUSSIONA differential diagnosis to the cause of the problem associated with the patient’s maxillary right cen-tral incisor was ambiguous. The patient did pres-ent with a history of trauma but the typical findings of wounds, injuries to the oral mucosa, fracture of the tooth, pulp exposure, displacement and mobil-

Figure 4: Calcium phosphosilicate (CPS) alloplast. Figure 5: Placement of Titanium Mesh.


Mahesh et al

ity 15 were not evident. The patient did report dis-placement but it would be difficult to conclusively state that as the reason for the problems. Another diagnosis could be localized aggressive periodonti-tis which exhibits itself typically with small amounts of plaque, mobility and migration of the molars and

incisors, increase in the size of the clinical crown and rapid progression.16 Despite the inconclu-sive etiology, the diagnosis of a hopeless tooth was made on sound clinical signs and symptoms

Alternate treatment modalities to our treat-ment plan included a removable partial denture,

Figure 6: Post-surgical CBCT scan.

16 • Vol. 8, No. 3 • May/June 2016

Mahesh et al

fixed partial dentures and resin bonded bridges (Maryland bridges). Removable partial dentures while an option can contribute to the loss of alveolar bone on both abutment and non-abut-ment teeth17 along with that the dissatisfaction rate of removable partial dentures is relatively high.18 On the other hand the use of fixed partial dentures would have required the unnecessary destruction of adjacent teeth to prepare them as abutments and loss of pristine tooth struc-ture. Another option would be a resin bonded bridge, which would reduce the amount of adja-cent tooth destruction. However, with a high incidence of pontic failure and debonding,19 we felt an implant would have been the best option.

Using the classification system pro-posed by Funato et al. 2007,20 the site in this case was Class IV which is characterized by vertical and buccal bone loss. It was thus necessary to perform bone and tissue aug-mentation so that optimal gingival profiling and a more esthetic result could be achieved.

Reconstruction of defects in the anterior part of the maxilla to enable implant place-ment is a challenging treatment. The alveolar ridge augmentation along with GBR has been introduced in recent years to re- establish an appropriate alveolar ridge width. Bone regen-eration in membrane protected defects heal in a sequence of steps that stimulated bone for-

Figure 7: Pre and post-surgical CBCT scans for comparison.


Mahesh et al

mation after tooth extraction. After blood clot formation, bone regeneration is initiated by the formation of woven bone initially along new blood vasculature at the periphery of the defect. The woven bone is subsequently replaced by lamellar bone, which results in mature bone anatomy. Ultimately, bone remodeling occurs with new, secondary osteons being formed.

Bone graft materials have been used to facili-tate bone formation within a given space by occu-pying that space and allowing the subsequent bone growth. The biologic mechanisms that sup-port the use of bone graft materials are osteo-conduction, osteoinduction and osteogenesis.

Barrier membranes are biologically inert materials that serve to protect the blood clot and prevent soft tissues cells (epithelium and connec-tive tissue) from migrating into the bone defect, allowing osteogenic cells to be established. Ver-tical increase of a narrow alveolar crest has been shown to be possible with membranes.21,22 Mem-branes have been manufactured from biocompat-ible materials that are both non resorbable and

resorbable. The advantage of a titanium barrier membrane (non-resorbable) is its ability to main-tain separation of tissues over an extended time. Unless the barrier is exposed, it can remain in place for several months to years but it requires a subsequent surgical procedure to remove them.

Bone augmentation and simultaneous implant surgery procedures allow clinicians to reconstruct alveolar bone deficiencies, preserve alveolar dimensions, and replace missing teeth with dental implants in a prosthetically driven position with natural appearance and function. The two year clinical results obtained in this case demonstrate CPS alloplast with GBR along with simultaneous implant placement to be a predictable and successful procedure to augment bone at sites exhibiting insufficient bone volume for implant placement under stan-dard conditions and proved to be a success-ful strategy for anterior esthetic rehabilitation.

CONCLUSIONPlacing dental implants in the maxillary anterior

Figure 8: Removal of titanium membrane revealing significant bone fill.

18 • Vol. 8, No. 3 • May/June 2016

Mahesh et al

region requires precise planning, surgery, and prosthetic treatment. This article has illustrated the steps needed to create ideal aesthetics in the maxillary anterior region. Rigorous treatment planning allows the implant surgeon, working with the restorative dentist, to select location, angulation, and spacing of dental implants to achieve ideal aesthetics. Treatment planning also dictates the necessity for hard- and soft-tissue grafting, which is often crucial for an ideal aesthetic result. Further, the prosthetic restora-tion of a dental implant must be ideal to achieve the desired aesthetic result. This article has discussed the importance of a comprehensive and interdisciplinary approach to treatment plan-ning, surgery, and restoration of dental implants in the maxillary anterior region of the mouth ●

CorrespondenceDr. Lanka Mahesh

Email: [email protected]

Figure 9: Final Prosthesis over implant placed in relation to tooth 11 (FDI tooth numbering system).

Figure 10: Radiograph at 14 months.


Mahesh et al

ADVERTISEADVERTISE 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.

WWW.JIACD.COM

DisclosureThe authors report no conflicts of interest with anything mentioned in this article

References1. Buser D,Martin W, Belser UC. Optimizing esthetics for implant res-

torations in the anterior maxilla: Anatomic and surgical consider-ations. Int J Oral Maxillofac Implants 2004;19(suppl):43–61.

2. Sigurdsson TJ, Hardwick R, Bogle GC, Wikesjö UM. Periodon-tal repair in dogs: space provision by reinforced ePTFE mem branes enhances bone and cementum regeneration in large supraalveolar defects. J Periodontol 1994;65:350-6.

3. Becker W, Becker BE, McGuire MK. Localized ridge augmentation using absorbable pins and e-PTFE barrier membranes: a new surgical technique. Case reports. Int J Periodontics Restorative Dent 1994;14:48-61.

4. Shanaman RH. The use of guided tissue regeneration to facilitate ideal prosthetic placement of implants. Int J Peri-odontics Restorative Dent 1992;12:256-65.

5. Buser D, Brägger U, Lang NP, Nyman S. Regeneration and enlargement of jaw bone using guided tissue regeneration. Clin Oral Implants Res 1990;1:22-32.

6. Nevins M, Mellonig JT. Enhancement of the damaged edentulous ridge to receive dental implants: a combination of allograft and the GORE-TEX membrane. Int J Periodontics Restorative Dent 1992;12:96-111.

7. Magne P, Magne M, Belser U. Natural and restorative oral esthetics. Part I: Rationale and basic strategies for success-ful esthetic rehabilitations. J Esthet Dent 1993;5:161-73.

8. Belser UC, Schmid B, Higginbottom F, Buser D. Outcome analysis of implant restorations located in the anterior maxilla: a review of the recent literature. Int J Oral Maxillofac Implants 2004;19 Suppl:30-42.

9. Buser D, Martin W, Belser UC. Optimizing esthetics for implant res-torations in the anterior maxilla: anatomic and surgical consider-ations. Int J Oral Maxillofac Implants 2004;19 Suppl:43-61.

10. Belser U, Buser D, Higginbottom F. Consensus statements and recommended clinical procedures regarding esthetics in implant dentistry. Int J Oral Maxillofac Implants 2004;19 Suppl:73-4.

11. Hjørting-Hansen E. Bone grafting to the jaws with special refer-ence to econstructive preprosthetic surgery. A historical review [in German]. Mund Kiefer Gesichtschir 2002;6:6–14.

12. Mellonig JT, Triplett RG. Guided tissue regeneration and endosseous dental implants. Int J Periodontics Restorative Dent 1993;13:108-19.

13. Doblin JM, Salkin LM, Mellado JR, Freedman AL, Stein MD. A histo-logic evaluation of localized ridge augmentation utilizing DFDBA in combination with e-PTFE membranes and stainless steel bone pins in humans. Int J Periodontics Restorative Dent 1996;16:120-9.

14. Lupovici J. Regeneration of the anterior mandible: a clinical case presentation. J Implant Reconstr Dent 2009;1:31-4.

15. Andreasen JO. Traumatic injuries of the teeth. chapter 2: examination and diagnosis of dental injuries. Munksgaard. Copenhagen 1972.

16. Carranza FA, Newman MG. Clinical periodontology 8th edi-tion. W. B Saunders Company. Philadelphia 1996.

17. Z lataric´ DK, Celebic´ A, Valentic´ -Peruzovic´ M. The effect of removable partial dentures on periodontal health of abutment and non-abutment teeth. J Periodontol. 2002;73(2):137-44.

18. Frank RP, Milgrom P, Leroux BG, Hawkins NR. Treatment outcomes with Mandibular removable partial dentures: A population based study of patient satisfaction. J Prosthet Dent. 1998;80(1): 36-45.

19. Berekally TL, Smales RJ. A retrospective clinical evalua-tion of resin-bonded bridges inserted at the Adelaide Den-tal Hospital. Aust Dent J. 1993;38(2):85-96.

20. Funato A, Salama MA, Ishikawa T, Garber DA, Salama H. Timing, position-ing, and sequential staging in esthetic implant therapy: a four-dimensional perspective. Int J Periodontics Restorative Dent. 2007;27(4):313-23.

21. Buser D, Hoffmann B, Bernard JP, Lussi A, Mettler D, Schenk RK. Evaluation of filling materials in membrane--protected bone defects. A comparative histomorphometric study in the mandible of miniature pigs. Clin Oral Implants Res 1998;9:137-50.

22. Simion M, Jovanovic SA, Tinti C, Benfenati SP. Long-term evalua-tion of osseointegrated implants inserted at the time or after verti-cal ridge augmentation. A retrospective study on 123 implants with 1-5 year follow-up. Clin Oral Implants Res 2001;12:35-45.

23. von Arx T, Hardt N, Wallkamm B. The TIME technique: a new method for localized alveolar ridge augmentation prior to placement of den-tal implants. Int J Oral Maxillofac Implants 1996;11:387-94.

Schneider et al

For more information, contact BioHorizonsCustomer Care: 1.888.246.8338 or shop online at www.biohorizons.com

SPMP12245 REV A SEP 2012

make the switch

The Tapered Plus implant system offers all the great benefits of BioHorizons highly successful Tapered Internal system PLUS it features a Laser-Lok treated beveled-collar for bone and soft tissue attachment and platform switching designed for increased soft tissue volume.

Laser-Lok® zoneCreates a connective tissue seal and maintains crestal bone

platform switchingDesigned to increase soft tissue volume around the implant connection

optimized threadformButtress thread for primary stability and maximum bone compression

prosthetic indexingConical connection with internal hex; color-coded for easy identification

Schneider et al

Removal and restoration of oral/dental tumors require multidisciplinary treatment planning and are very challenging for the

patient, clinician and dental technician. Today CAD/CAM technology and advances in dental technology frequently allow for a successful and predictable treatment outcome for the patient. A multidisciplinary approach to a patient’s surgi-cal and prosthodontic rehabilitation will be pre-sented. The use of a CAD/CAM designed and milled titanium framework and resultant definitive

prosthesis will be discussed. The coordination of treatment with the surgeon, prosthodontist and dental technician are paramount in the success-ful treatment of the patient. The prosthesis fab-rication approach described has proven superior to the previous techniques of waxing and casting metallic frameworks in regards to time, accuracy and successful long-term predictability for the patient. The surgical and prosthodontic treat-ment of a patient presenting with a mandibular central giant cell granuloma will be discussed.

Treatment of a Central Giant Cell Granuloma of the Mandible

Robert Schneider, DDS, MS, FACP, FAAMP1 • Steven L. Fletcher, DDS2

Kyle M. Stein, DDS2

1. Professor Emeritus, University of Iowa Hospitals and Clinics, Hospital Dentistry Institute, Division of Maxillofacial Prosthodontics, Iowa City, Iowa, USA

2. Associate Professor, University of Iowa Hospitals and Clinics, Hospital Dentistry Institute, Division of Oral and Maxillofacial Surgery, Iowa City, Iowa, USA

Abstract

KEY WORDS: Oral tumors, dental implants, CAD/CAM frameworks, partial mandibulectomy, central giant cell granuloma, grafting


22 • Vol. 8, No. 3 • May/June 2016

Schneider et al

INTRODUCTIONA 21 year old female was referred to the Uni-versity of Iowa Hospitals and Clinics (UIHC), oral and maxillofacial surgery clinic by an out of town oral surgeon. She presented with a his-tory of endodontic therapy on tooth #29 with a resultant apical radiolucency. The lesion was followed in that office with serial radiographs for several months until the patient began to notice pain and swelling in the right side of her

mandible (Fig 1). The lesion was diagnosed via biopsy as a central giant cell granuloma (CGCG), she was then referred to UIHC for definitive surgical and prosthodontic treatment.

A CGCG is a non-malignant lesion which can be rapidly enlarging and destructive to the bone and teeth. It is twice as likely to affect women and is more likely to occur in 20-40 year old individuals. CGCG’s are more com-mon in the mandible and often cross the mid-

Figure 1: Initial panoramic radiograph of lesion in the right posterior mandible.

Figure 2: Radiograph of lesion post extraction pre-enucleation.

Figure 3: Radiograph of area with AICG in place following enucleation of lesion.

Figure 4: Intra oral frontal view of defect area following the AICG.


line. They are characterized by large lesions that expand the cortical plate and can resorb roots and move teeth. Radiographically it appears as multilocular radiolucencies of bone. CGCG was classified by the World Health Organization in 2005 as a rarely aggres-sive idiopathic benign intraosseous lesion that occurs almost exclusively in the jaws.1

PATIENT TREATMENTThe patient’s medical history was benign with a dental history consisting of orthodontic treat-ment completed at the age of 16 years of age with good results and stable occlusion and the previously mentioned endodontic treatment of tooth #29. A CT scan of the mandible was ordered and showed a large, expansile lesion of the mandible extending from teeth #22 to #31 with erosion through both buccal and lingual

Figure 5: Occlusal view of mandibular defect area. Figure 6: Diagnostic wax up on casts, occlusal view.

Schneider et al

24 • Vol. 8, No. 3 • May/June 2016

Schneider et al

cortices. Multiple treatment options were dis-cussed including intralesional steroid injections, enucleation and resection. Following detailed discussion with the patient the decision was made to treat the lesion conservatively, which would include extraction of the involved teeth, then enucleation of the lesion.2-3 Once early recurrence of the tumor was ruled out the defect would then be constructed with an anterior iliac crest bone graft (AICG) to the area for future

implant placement and restoration (Figs. 2-3). The patient was also referred to the maxillofacial prosthodontic clinic at UIHC prior to the surgi-cal procedure to discuss the restorative options and timing of the procedures (Figs. 4-5).

At the prosthodontic evaluation mounted diagnostic casts were made and a discussion with the patient on the treatment options was undertaken. The family was given the option of restoration with a removable partial denture

Figure 7: Intraoral try-in of wax up for patient approval. Figure 8: Occlusal view of restrictive surgical guide.

Figure 9: Frontal view of healed implant placement with definitive abutments in place.

Figure 10: Master cast with implants, occlusal view.


or dental implant supported fixed partial den-ture with the understanding treatment with den-tal implants would require an AICG to provide adequate alveolar volume for implant placement in the optimal position for the fixed prosthe-sis. The patient was enthusiastic about pro-ceeding with the plan for restoration with the implant supported fixed partial denture (Fig 6).

After the treatment plan was established, teeth #24-31 were removed. Following six

weeks to allow for adequate soft tissue heal-ing, the lesion was enucleated via an intraoral approach. The lesion was intimately associated with the inferior alveolar nerve and as a result, the patient did experience some right V3 paresthesia following enucleation. Several months after enucleation, a small infection was noted associated with tooth #25. The tooth was removed at that time and the patient had an uneventful recovery from that point.

Figure 11: Wax up on master cast, lateral view. Figure 12: Lateral view of scan in laboratory for framework design to provide optimal material and tooth support.

Figure 13: Occlusal view of scan in laboratory for framework design to provide optimal contours material and tooth support.

Figure 14: Occlusal view of completed framework on master cast.

Schneider et al

26 • Vol. 8, No. 3 • May/June 2016

Schneider et al

Repeat panoramic radiographs at one year and at 18 months showed no recurrence of the tumor and at 20 months post enucleation, an AICG was secured in the defect area.

The decision was made that four dental implants would provide adequate support for a screw retained fixed partial denture processed in injection molded/heat polymerized acrylic resin.4-7 A porcelain fused to metal restora-tion or all zirconium restoration could also be

fabricated, however the prosthodontic author prefers processed acrylic resin for this type of reconstruction due to ease of adjustment, rep-arability, lack of abrasiveness to the opposing occlusion, relative ease of fabrication and the possibility of recurrence of the CGCG requir-ing removal/modification of the prosthesis.

Planning for the definitive implant place-ment was completed through the evaluation of mounted diagnostic casts of the grafted mandi-ble and a diagnostic wax-up that was tried in the patient’s mouth for verification of occlusion and esthetics. The prosthodontic treatment plan-ning discussion included the oral surgeon(s) and dental technician. Utilizing the wax-up a restrictive surgical guide was fabricated to allow fabrication of a screw retained implant supported fixed partial denture (Figs 7-8). In consultation with the oral surgeon it was deter-mined we would place a narrow diameter implant (3.3mm) in the area of #25, standard diameter implants (4.1 mm) in the area of #27 and 28, and a wide diameter implant (4.8 mm) in the area of #30. The restrictive surgical guide

Figure 15: Occlusal view of framework with completed wax up prior to spruing and processing.

Figure 16: Completed prosthesis as returned from the dental laboratory.

Figure 17: Apical view of completed prosthesis showing convex gingival contour to to facilitate optimal oral hygiene procedures.


Figure 18A: Occlusal view of completed prosthesis. Figure 18B: Frontal view of completed prosthesis.

Figure 19: Frontal view of patient smile with completed prosthesis in place.

Figure 20: Panoramic radiograph confirming acceptable fit of framework and establishing baseline alveolar bone levels for future evaluations.

was fabricated using clear polymethyl methac-rylate. Parallel holes were drilled in the guide for placement of the restrictive guide sleeves. It was also determined that tooth #24 had inad-equate alveolar support on the mesial from the previous surgeries and was extracted at the time of implant placement. The oral surgeon placed the implants using standard osteotomy preparation procedures utilizing the restric-tive guide without complications. A one stage

surgical approach was utilized. The implants were allowed to heal for 8 weeks before mak-ing final impressions The patient maintained good oral hygiene and continued with chlorhexi-dine oral mouth rinse applied locally to the sur-gical site during the healing period (Fig. 9).

The final implant level impression was made with a custom tray and polyvinyl silox-ane impression material to be mounted on the articulator with a facebow. A verification

Schneider et al

28 • Vol. 8, No. 3 • May/June 2016

Schneider et al

index was fabricated in the laboratory for intra-oral try-in at the maxillo-mandibular relation-ship appointment to confirm the accuracy of the master cast. Following the verification pro-cess the tooth arrangement was completed on the master cast trying to as closely as pos-sible duplicate the patient’s pre surgery tooth position (Figs. 10-11). Following confirmation of the intraoral accuracy of the wax prosthetic tooth arrangement by the prosthodontist and the patient, the wax-up and master cast were sent to the dental laboratory to be scanned, the framework designed and sent to a milling facility to fabricate the prosthesis sub structure with the design as verified by the prosthodon-tist and the technician (Figs. 12-13). A wax try-in which would also include the final framework can also be done, however the prosthodontic author has not requested this step from the laboratory for several years due to the verifica-tion index confirmation of master cast accuracy. The prosthodontist requested a “high-water” pontic design for this patient to help facili-tate oral hygiene procedures which was included in the framework design consideration.

A multitude of design concepts are avail-able and can be utilized.8 The technician and the prosthodontist can both evaluate the design with a 3D viewing program that allows evaluation from any angle with or with-out the replacement tooth overlay. This allows critical analysis of the framework design to provide satisfactory support/retention and thickness of material of the final prosthesis.

The framework is milled using titanium alloy (Ti6AI4V) (Fig. 14). The prosthetic teeth are added to the framework according to the definitive wax-up and processed utilizing an

injection molded technique which helps elimi-nate stress/potential distortion to the frame-work (Fig. 15). When the polymerization and deflasking process is complete the pros-thesis can then be finished a routine man-ner and returned for delivery to the patient.

At completion the prosthesis was deliv-ered from the laboratory for insertion (Figs. 16-17). The healing caps were removed and the prosthesis went to place passively fol-lowing placement of the appropriate screw retained abutments (Figs. 18A, 18B, 19). The narrow implant component was milled to fit directly to the implant due to the design of the top of the implant. The occlusion was checked and very minor adjustments made with a laboratory remount procedure. The patient was given oral hygiene instructions and the appropriate hygiene armamentaria were pro-vided to her. A delivery radiograph was taken to verify accuracy of fit of the framework and to serve as a baseline evaluation for alveo-lar bone levels around the implants (Fig. 20).

CONCLUSIONThe reconstruction of oral tumors requires the use of a multi-disciplinary approach which can lead to a very predictable outcome for the patient. Every member of the surgical, prosth-odontic and dental technician team is critical to the success of the outcome. Surgical, prosth-odontic and dental technology techniques and material use are advancing rapidly. All mem-bers of the implant/reconstruction team must be aware of these advancements and work closely together to understand the limits and possibilities of treatment. The successful sur-gical and prosthodontic reconstruction of


an oral tumor was illustrated with a very posi-tive outcome and predictable longevity. This allowed the patient to return to near normal function with an excellent phonetic/esthetic outcome very near her pre diagnosis situation.

We recommend continued follow-up and annual radiographs to evaluate the possibility of reoccurrence of the CGCG and observation of the alveolar bone levels around the implants. She will also see her general dentist twice annual for routine prophylaxis and scaling. ●

Correspondence:Dr. Robert SchneiderUniversity of Iowa Hospitals and Clinics, Hospital Dentistry Institute, Division of Maxillofacial Prosthodontics, 200 Hawkins DriveIowa City, IA 52242-1049Phone: 319-384-8655 • Fax: 319-353-6923Email: [email protected]

AcknowledgementThank you to Danny Roberts, CDT for his skill, expertise and advice in the scanning and design/finishing of the definitive prosthesis.

References1. Nicolai G, Lore B, Mariani G, et al. Central giant

cell granuloma of the jaws. J Craniofac Surg. 2010;21(2):383-6.

2. Kermer C, Millesi W, Watzke IM. Local injection of corticosteroids for central giant cell gramuloma. A case report. Int J Oral Maxillofac Surg. 1994;23:366-8.

3. Pogel AM. The diagnosis and management of giant cell lesions of the jaws. Ann Maxillofac Surg. 2012 ;2(2):102-6.

4. Taylor TD: Clinical maxillofacial Prosthetics. Chicago, Quintessence, 2000.

5. Moore D, Mitchell D. Rehabilitating dentulous hemi-mandibulectomy patients. J Prosthet Dent 1976;35(2):202-206.

6. Schneider, R. Fridrich, K, Funk G. Complex mandibular reconstruction of a partial mandibulectomy fibula free graft reconstruction. J Prosthet Dent 2013;110(3):223- 227

7. Schneider, R, Fridrich, K, Chang, K. Complex mandibular reconstruction of a self- inflicted gun shot wound: A patient report. J Prosthet Dent 2012;107(3):158-162.

8. Schneider R. Restoration of an acquired mandibular defect secondary to a neoplasm excision. Inside Dentistry 2007;3(8):78-82.

ATTENTION PROSPECTIVE AUTHORSJIACD 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]

Schneider et al

Holtzclaw

DID YOU KNOW?Roxolid implants deliver more treatment options

Roxolid is optimal for treatment of narrow interdental spaces.

Case courtesy of Dr. Mariano Polack and Dr. Joseph Arzadon, Gainesville, VA

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

www.straumann.us

Holtzclaw

Background: Immediately loaded full arch dental implant restorations rely on immedi-ately delivered acrylic provisional restorations for esthetics, masticatory function, and cross arch stabilization. These provisional restora-tions may be in function from 4-12 months prior to delivery of a definitive final restoration. Fracture of the acrylic provisional restoration during the healing phase has been reported anywhere from 11-40% of cases in dental lit-erature. Recent studies have suggested that reinforcement of the provisional restoration with a variety of materials may improve rigidity and decrease fracture rates. The purpose of this retrospective review is to evaluate if reinforce-ment of immediately loaded full arch transi-tional dental implant restorations has any effect on fracture rates during the healing phase.

Case Series: A retrospective chart review was

conducted for all patients treated with the All-On-4 treatment concept at the private practice of the author in Austin, Texas between January 2014 and March 2016. A total of 69 men and 112 women with a mean age of 61.6 years were treated with the All-On-4 treatment con-cept using 1182 dental implants. A total of 243 dentate and 14 edentulous arches were treated. Non-reinforced transitional restorations had a fracture rate of 16.14% while reinforced transitional restorations had a fracture rate of 4.17%. There was no difference in overall den-tal implant survival between the two groups.

Conclusions: Reinforcement of All-On-4 acrylic provisional restorations with inter-plaited steel wire reduces fracture rates. Fur-ther studies are warranted to investigate whether or not these reduced fracture rates have any effect on dental implant survival.

The Effects of Reinforcement on the Fracture Rates of Provisional All-On-4 Restorations: A Retrospective Report

of 257 Cases Involving 1182 Dental Implants

Dan Holtzclaw, DDS, MS1

1. Private practice, Austin, Texas, USA

Abstract

KEY WORDS: Dental implants, prosthodontics, immediate dental implant loading, temporary dental restoration, dental materials


32 • Vol. 8, No. 3 • May/June 2016

BACKGROUNDSince its initial report in dental literature over 12 years ago,1 the All-On-4 treatment concept has proven to be a predictable method for full arch immediately loaded dental reconstruction. One hall-mark of this procedure is “immediate” delivery of a screw retained provisional restoration within 2-24

hours of dental implant placement.2-4 In addition to providing immediate masticatory function for the patient, the provisional restoration helps to stabi-lize the newly placed dental implants by improving stress distribution through cross arch stabiliza-tion.5-7 Previously published studies have indicated that these provisional restorations may be used

Figure 1: Holtzclaw Class 1 All-On-4 restoration fracture. Figure 2: Holtzclaw Class 2 All-On-4 restoration fracture.

Figure 3: Holtzclaw Class 3 All-On-4 restoration fracture. Figure 4: Holtzclaw Class 4 All-On-4 restoration fracture.

Holtzclaw


anywhere from 4-12 months prior to delivery of a final prosthesis2-4,7 and that fracture rates up to 40% may occur during this timeframe.8 A recent num-ber of studies suggest that reinforcement of transi-tional All-On-4 restorations with materials such as braided wire6 or various fibers8 may improve rigid-ity of the prosthesis. Accordingly, the purpose of this retrospective review is to evaluate if reinforce-ment of All-On-4 transitional restorations has any effect on fracture rates during the healing phase.

CLINICAL PRESENTATIONA retrospective chart review was conducted for all patients treated with the All-On-4 treatment con-cept at the private practice of the author in Aus-tin, Texas between January 2014 and March 2016. A total of 69 men and 112 women with a mean age of 61.6 years were treated with the All-On-4 treatment concept using 1182 dental implants. A total of 243 dentate and 14 edentulous arches were treated. All patients provided both verbal and signed consent prior to treatment. As this was a retrospective chart review, there were no exclusionary criteria. All-On-4 provisional fractures

were graded according to Holtzclaw All-On-4 Fracture Classification7 (Table 1, Figures 1-4) and dental implant survival was determined accord-ing to the Malo Clinic Survival Criteria4 (Table 2).

CASE MANAGEMENTAll provisional restorations were fabricated in a similar fashion. Following the surgical process of the All-On-4 style dental implant surgery, a con-ventional acrylic complete denture was adjusted to accommodate the dental implant/multi-unit abut-ment/transitional coping complex (Figure 5). Jet acrylic (Land Dental Manufacturing, Wheeling, Illi-nois, USA) was mixed according to manufacturer’s directions and injected around the transitional cop-ings intraorally (Figure 6). Once the transitional copings were rigidly fixed to the acrylic denture with set Jet acrylic, the denture was removed from the mouth and finished extraorally. For non-rein-forced provisional prostheses, the restoration was finished with additional Jet acrylic using a heated pressure pot set to 20PSI, contoured, and pol-ished (Figure 7). For reinforced provisional pros-theses, an insert consisting of two 1mm diameter

Table 1: Holtzclaw Classification7 for All-On-4 Restoration Fractures

Fracture Classification Fracture Description

Class 1 Fracture of tooth only (Figure 1)

Class 2 Fracture including the acrylic base located anterior to the distal most implant transitional coping (Figure 2)

Class 3 Fracture including the acrylic base located at or distal to the most distal transitional coping (Figure 3)

Class 4 Any fracture that does not clearly fit into Class 1-3 (Figure 4)

Holtzclaw

34 • Vol. 8, No. 3 • May/June 2016

Holtzclaw

interplaited steel wires was custom bent with orth-odontic pliers and secured within the prosthesis using Jet acrylic (Figure 8). The reinforced pro-visional prostheses were then contoured and pol-ished in the same manner as the non-reinforced prostheses (Figure 9). Both types of prostheses were then delivered to patients (Figures 10, 11) and screws were torqued to 15Ncm accord-ing to manufacturer’s directions. Screw access holes were filled with Teflon tape and sealed with either composite or Gingifast (Zhermack SpA, Italy) depending on the location of the hole.

CLINICAL OUTCOMESA total of 257 arches were treated using 1182 den-tal implants. The initial 161 arches were treated with non-reinforced transitional restorations while the latter 96 arches were treated with reinforced restorations. Fracture rates of non-reinforced tran-

sitional restorations were 16.14% (26 of 161) while reinforced restorations had a fracture rate of 4.17% (4 of 96) prior to delivery of final restoration. Frac-ture types according to the Holtzclaw classification are listed in Table 3. At the time of final restoration, 13 dental implant failures were noted in non-rein-forced cases (13/740 = 98.24% dental implant survival rate) while reinforced cases had 2 failures (2/442 = 99.17% dental implant survival rate).

DISCUSSION“Immediate” delivery of a provisional screw retained prosthesis within 2-24 hours is a proven and effec-tive technique for All-On-4 style dental implant pro-cedures.2-4 The cross arch stabilization provided by the provisional restoration improves stress distribu-tion among the osseointegrating dental implants6,7

and improves survival rates for implants with less than desirable initial torque values.5,9 In the event

Table 2: Malo Clinic Survival Criteria4 for Dental Implants

Criteria Number Criteria Description

Criteria 1 The dental implant fulfilled its purported function as support for reconstruction

Criteria 2 The dental implant was stable when individually and manually tested

Criteria 3 No signs of infection were observed around the dental implant

Criteria 4 No radiolucent areas were observed around the dental implant

Criteria 5 The dental implant demonstrated good esthetic outcome of rehabilitation

Criteria 6 The dental implant allowed for construction of the implant supported fixed prosthesis


Holtzclaw

of provisional prosthesis fracture, cross arch sta-bilization is lost and may have deleterious effects on osseointegrating dental implants.7 Further-more, fracture of All-On-4 provisional restorations is unsettling to the patient as it disrupts mastica-tory function, marginalizes esthetics, and requires an additional appointment to repair the prosthesis.

Provisionalized All-On-4 restorations typically consist of a traditional all-acrylic complete denture that is modified to fit newly placed dental implants

and their associated multi-unit abutments/transi-tional copings. Upon modification, the conven-tional denture is converted into an all-acrylic bridge that ranges in thickness between 9-12mm.7 Frac-ture of All-On-4 acrylic provisional restorations is a known risk factor with rates ranging from 11-40% in published dental literature.10,11 Over the past 20 years, a number of attempts have been made to improve the fracture resistance of all-acrylic restorations with reinforcement materials such as

Figure 5: Conventional acrylic denture modified to fit dental implant/multi-unit abutment/transitional coping complex.

Figure 6: Transitional coping secured to conventional acrylic denture using Jet acrylic.

Figure 7: Polished non-reinforced transitional restoration prior to delivery.

Figure 8: Interplaited steel wire inserted into transitional restoration.

36 • Vol. 8, No. 3 • May/June 2016

woven glass fibers,8,13 woven polyethylene fibers,13 nylon,12 and metal.6,8,13-15 A recent in vitro study by Li et al.8 examined the effects of reinforcement on flexural properties of All-On-4 provisional fixed den-ture base resin using a 3-point loading test. The results of this study indicated that reinforcement of All-On-4 provisional restorations not only increased fracture resistance, but also changed typical loca-tions of the fractures. The in vitro findings of Li et al. are supported by the findings of the current ret-rospective study in which All-On-4 provisional res-

torations reinforced with interplaited steel wire had lower fracture rates than non-reinforced provisional restorations. Furthermore, the nature of these frac-tures also changed according to their Holtzclaw fracture classification grouping. Although fracture rates were reduced for reinforced provisional res-torations compared to non-reinforced restorations, dental implant survival at the time of final prosthe-sis delivery was similar amongst the two groups.

SUMMARY

Reinforcement of All-On-4 acrylic provisional restorations with interplaited steel wire reduces fracture rates. Further studies are warranted to investigate whether or not these reduced fracture rates have any effect on dental implant survival.of the provisional restoration is performed. ●

Figure 9: Polished reinforced transitional restoration prior to delivery.

Figure 10: Radiograph of non-reinforced transitional restoration after delivery.

Figure 11: Radiograph of reinforced transitional restoration after delivery

Correspondence:Dan Holtzclaw, DDS, MS11921 Palisades Pkwy

Austin, TX 78732

[email protected]

Holtzclaw


Table 3: Fracture types according to Holtzclaw Fracture Classification7

Fracture Class Non-reinforced Prosthesis Reinforced Prosthesis

Class 1 16 4

Class 2 0 0

Class 3 10 0

Class 4 0 0

AcknowledgementsNone. The author reports no conflicts of interest with anything mentioned in this article.

References1. Malo P, Ranger B, Nobre M. “All-On-4” immediate

function concept with Branemark System implants for completely edentulous mandibles: A retrospective clinical study. Clin Implant Dent Relat Res 2003;5:2-9.

2. Agliardi E, Clerico M, Ciancio P, Massironi D. Immediate loading of full-arch fixed prostheses supported by axial and tilted implants for the treatment of edentulous atrophic mandibles. Quintenssence Int 2010;41:285-293.

3. Malo P, de Araujo Nobre M, Lopes A, Francichone C, Rigolizzo M. “All-On-4” immediate function concept for completely edentulous maxillae: a clinical report on the medium (3 years) and long term (5 years) outcomes. Clin Implant Dent Relat Res 2012;14:139-150.

4. Malo P, Araujo Nobre M, Lopes A, Rodrigues R. Double full arch versus single full arch four implant supported rehabilitations: A retrospective 5 year cohort study. J Prosthodont 2015;24:263-270.

5. Jensen O, Adams M. Secondary stabilization of maxillary M4 treatment with unstable implants for immediate function: biomechanical considerations and report of 10 cases after 1 year. Int J Oral Maxillofac Implants 2014;29:232-240.

6. Yamaguchi K, Ishiura Y, Tanaka S, Baba K. Influence of rigidity of a provisional restoration supported on four immediately loaded implants in the edentulous maxilla on biomechanical bone-implant interactions under simulated bruxism conditions: a three-dimensional finite element analysis. Int J Prosthodont 2014;27:442-450.

7. Holtzclaw D, Telles R. Analysis of fractures in All-On-4 provisional restorations using a standardized classification system. J Implant Adv Clin Dent 2015;7:17-25.

8. Li BB, Xu JB, Cui HY, Lin Y, Di P. In vitro evaluation of the flexural properties of All-On-4 provisional fixed denture base resin partially reinforced with fibers. J Dent Mat 2016;35:264-269.

9. Degidi M, Daprile G, Piattelli A. Implants inserted with low insertion torque values for intraoral welded full-arch prosthesis: 1-year follow-up. Clin Implant Dent Relat Res 2012;14:39-45.

10. Francetti L, Agliardi E, Testori T, Romeo D, Taschieri S, Del Fabbro M. Immediate rehabilitation of the mandible with fixed full prosthesis supported by axial and tilted implants: interim results of a single cohort prospective study. Clin Implant Dent Relat Res 2008;10:255-263.

11. Pomares C. A retrospective study of edentulous patients rehabilitated according to the ‘all-on-four’ or the ‘all-on-six’ immediate function concept using flapless computer-guided implant surgery. Eur J Oral Implantol 2010;3:155-163.

12. John J, Gangadhar SA, Shah I. Flexural strength of heat-polymerized polymethyl methacrylate denture resin reinforced with glass, aramid, or nylon fibers. J Prosthet Dent 2001;86:424-427.

13. Heidari B, Firouz F, Izadi A, Ahmadvand S, Radan P. Flexural Strength of Cold and Heat Cure Acrylic Resins Reinforced with Different Materials. J Dent (Tehran) 2015;12:316-323.

14. Polyzois GL, Andreopoulos AG, Lagouvardos PE. Acrylic resin denture repair with adhesive resin and metal wires: effects on strength parameters. J Prosthet Dent 1996;75:381-387.

15. Vallittu PK, Lassila VP. Reinforcement of acrylic resin denture base material with metal or fibre strengtheners. J Oral Rehabil 1992;19:225-230.

Holtzclaw

Elkerdawy et al

Click For Our Quantity

Discount Options

www.exac.com/QuantityDiscountOptions

© 2

012

Exac

tech

, Inc

.

Oralife is a single donor grafting product processed in accordance with AATB standards as well as state and federal regulations (FDA and the states of Florida, California, Maryland and New York). Oralife allografts are processed by LifeLink Tissue Bank and distributed by Exactech Inc.1. Data on file at Exactech. 2. McAllister BS, Hagnignat K. Bone augmentation techniques. J Periodontal. 2007 Mar; 78(3):377-96. 3. Blum B, Moseley J, Miller L, Richelsoph K, Haggard W. Measurement of bone morphogenetic proteins and

other growth factors in demineralized bone matrix. Orthopedics. 2004 Jan;27(1 Suppl):s161-5.

What’s Your Sign?

www.exac.com/dental1-866-284-9690

• Cost-effectivegraftingmaterial

• Validatedtomaintainosteoinductivityand biomechanical integrity1

• MixtureofDBMwithmineral-retained cortical and cancellous chips, processed in a manner to retainthenaturally-occuringgrowthfactors(BMP)andbeaconductivelattice – all in one product1,2,3

NEW Oralife Plus Combination Allograft available now!

MEET OUR

PlusA QUALITY COMBINATION

Elkerdawy et al

Background: Over denture treatment modal-ity either tooth supported or implant supported aim to improve the quality of life regarding function and self-image. The main difference between implant supported and tooth sup-ported overdenture is the nature of their attach-ment to bone which is different in both cases due to the presence of periodontal ligament present in tooth supported overdenture which is clearly absent in the case of osseointegrated implants. The aim of this study was to com-pare the effect of difference in support type of the overdenture on the maximum biting force.

Methods: 20 patients were selected ten of which were completely edentulous patients where two implants were installed in the man-dibular canine area. The other ten patients were presented with two residual canines in their lower arches. For the implant supported group,

overdentures were fabricated and were retained by a locator attachment. Regarding the tooth supported group, the canines were prepared to receive a locator attachment over which an overdenture was fabricated. The biting force was recorded for both groups at prostheses insertion 3 months and 6 months post insertion.

Results: in both groups there was statis-tically significant increase in biting force after 3 months follow up period. Moreover, root supported overdenture showed signifi-cantly higher biting force than implant sup-ported through the whole follow up period. Conclusion: the biting force increased in both root and implant supported over-dentures, meanwhile the biting force was higher in the root supported group.

Effect of Root Support versus Implant Support on the Biting Force of Attachment Retained

Mandibular Overdentures

Dr. Maha W. Elkerdawy1 • Dr. Nancy N. Elsherbini2

1. Assistant Professor of Removable Prosthodontics. Faculty of Oral and Dental Medicine, Cairo University.

2. Lecturer of Removable Prosthodontics. Faculty of Oral and Dental Medicine, Cairo University.

Abstract

KEY WORDS: Biting force, overdenture, implant overdentures, and locator attachment


40 • Vol. 8, No. 3 • May/June 2016

INTRODUCTIONAn overdenture is a complete or removable par-tial denture that has one or more tooth roots or implants to provide support.1 A very important advantage in natural teeth is the presence of the periodontal ligament PDL, which is the natu-ral mechanism of attachment of the tooth to its socket in the alveolar bone.2 One of the main func-tions of the PDL is to provide sensory feedback in the masticatory cycle during chewing. Humans are capable of detecting the presence of very small particles between the occlusal surfaces of teeth.3,4 Forces transmitted to the bone are either axial forces or horizontal tipping forces that are applied to a tooth, a tendency toward displace-ment of the root into the alveolus occurs with the axial load, while horizontal / tipping forces result in two phases of tooth movement. The first occurs within the confines of the periodontal ligament, while the second produces a displacement of both the facial and lingual bony plates.4 The PDL mechanoreceptors are particularly important for neuromuscular and tactile activity in the stomato-gnathic system as it is responsible for percep-tion of load. When remaining roots are retained to support an over denture all these advantages of the PDL will be preserved also when this is com-bined by the use of dental attachments this will also improve retention which will magnifies the efficiency of the over denture therapy.6,7 Insertion of two implants in completely edentulous patients will improve support which is a great problem for those patients especially for those suffering from severely resorbed ridges either due to long stay without treatment, under serviced dentures or due to a debilitating disease that affected the bone.8 If the implant placement was combined with the use of attachment so the mechanical retention of

the overdenture will much improve.9 Individual bite force level determination has been widely used in dentistry, mainly to understand the mechanism of mastication for evaluation of the therapeutic effects of different prosthetic devices and pro-viding reference values for studies on the biome-chanical function of prosthetic devices.10,11 The functional state of the masticatory system can be evaluated by the Bite force that results from the action of jaw elevator muscles modified by the craniomandibular biomechanics.12,13 Therefore this study was conducted to compare the effect of different support types on the maximum bit-ing force of attachment retained overdentures.

MATERIALS AND METHODSPatient SelectionTwenty male patients were selected from the outpatient clinic, Removable prosthodontic department, faculty of oral and dental medi-cine, Cairo University. Ten patients were pre-sented with completely edentulous upper and lower arches (group I); the other ten patients were presented with upper completely edentu-lous arches against remaining two mandibular canines (group II) .Male patients were selected to avoid any hormonal disturbance that may affect the bone quality that may affect the suc-cess of the clinical outcome. The patient ages ranged from 45-55 years of age so that the patients possessed a well-developed muscu-lar system. Also all patients were medically free from debilitating diseases that may affect the bone quality and quantity as diabetes mellitus and parathyroid disorders, patients were free from diseases that might affect the muscle coor-dination as Parkinson’s disease to make sure no excessive uncontrolled forces are exerted

Elkerdawy et al


during measuring the biting force. Cases with normal Angle’s class I were selected to obtain proper direction of force with the long axis of the teeth. Smokers were excluded as smoking, beside its effect on the hard and soft marginal tissues, could lead to anoxia of the oral cavity, a thing which could be associated with high level of marginal bone loss leading to poor prognosis for the treatment success. Canines were cho-sen owing to their strategic position in the arch and their strong roots, thus provide good den-ture support and stability. They also help in pre-serving bone in the anterior region of the dental arch which is more susceptible to resorption.

Group IDelivered mandibular dentures were duplicated to produce a clear acrylic resin radiographic tem-plate to evaluate the amount of the bone available at the proposed implant sites. After administrat-ing peripheral infiltration anaesthesia, the surgi-cal template was used to place two immediately loaded 3.7 in diameter and 13mm in length implants (Legacy, Spectra system, Implant direct, U.S.A.) in their prepared implant beds at the

canine area on each side using the punch tech-nique. Implants were left for 3 months to osseo-integrate, after which patients were recalled. The placed implants were exposed and two Loca-tor attachments were screwed on the implants and tightened in place (fig.1). White block out spacers were slipped around the Locator abut-ments to facilitate the pickup procedure. Then the metal housings with their black processing caps were placed directly over the Locator abut-ments and the denture was then properly relieved opposite to the attachment sites and assured for proper seating. A hole was made from the lin-gual aspect to allow for escape of excess resin. Cold cure resin (Repair acrylic Garreco. P.O. Box 1258, Herber springs. USA) was placed in the relieved areas of the denture which was seated in position and the resin was left to polymerize while the patients were instructed to close in cen-tric relation with minimal pressure. The denture was removed with the metal housings picked up in its fitting surface. The chosen Locator replace-ment male was firmly pushed into the metal hous-ing using the male seating tool then a click was heard confirming the full seating of the male part.

Figure 1: Locator attachment in patients’ mouth. Figure 2: Canines prepared to receive attachment.

Elkerdawy et al

42 • Vol. 8, No. 3 • May/June 2016

Group II The two canines were reduced to within 1.0 mm supragingivally by the use of the Locator The locator root attachment kit (Zest Anchors, Inc. Escondido, CA 92029 USA). The top of the root surface was prepared as flat as possible from the mesial to the distal portion of the tooth. A white plastic reference ring was adjusted on the pilot drill to a depth of 1.0 mm longer than the length of the female post and drilling was performed in the patient mouth. The counter-sink diamond bur was used making a very shal-low recessed seat on the root surface (fig.2). Root surface Paralleling post was used to detect parallelism of the preparation. The loca-tor was then cemented in the root (fig.3) using glass ionomer cement (Glass ionomer cement, 3M Center Building 275-2SE-03St. Paul, MN 55144-1000, U.S.A.) with locator post attached to it. The spacer was then placed around the locator’s neck and the black processing cap was attached over the locator. A recess was then prepared in the fitting surface of the den-ture opposite to the processing cap. Chair side self-cured repair material acrylic resin (Repair

acrylic Garreco. P.O. Box 1258, Herber springs. USA) was mixed and placed in the prepared recess.The denture was then seated into the patient’s mouth and the patient was guided to close in centric occlusion position maintain-ing a proper relationship with the opposing arch, excessive occlusal pressure was avoided. After the acrylic resin has cured the denture was removed from the patient’s mouth, excess acrylic was removed and the white spacer was discarded.The locator male removal tool was then used to remove the black male process-ing cap. The chosen Locator replacement male was firmly pushed into the metal housing using the male seating tool then a click was heard confirming the full seating of the male part. The denture was then placed in position and mild refinement of occlusion was done using articulating paper. The patient was then guided for how to insert and remove his denture.

Recording the Maximum Biting ForceFor both groups the biting force was measured immediately on the day of prostheses insertion 3 months and then 6 months post insertion. Bit-ing force was measured using iloadstar sensor (Loadstar sensors. 453 Riverdale Drive, Moun-tain View, CA94043). The iloadstar sensor was used to measure the maximum biting force; the sensor was prepared before reading by plac-ing it in the working environment for 24 hours before measurement to avoid errors in calibra-tion due to sudden changes in temperature. The patients were asked to sit in an upright position so that the force application direction is vertical, and the dome shaped top of the sensor was placed in the occlusal embrasure between the upper second premolar and the adjacent first

Figure 3: Locator cemented in place.

Elkerdawy et al


molar as this area allows the patient to exert maximum controlled force. The maximum capac-ity of the sensor is 907 N so care was taken not to overload the sensor beyond the rated value. The impact of the force was measured to detect the relative difference in the perception of force concerning the difference in the nature of attachment to the bone. One-way Analysis of Variance (ANOVA) test and the Tukey-Kramer Multiple Comparisons test were used to investi-gate significant differences among the groups.

RESULTSEffect of time on the two groupsRegarding the effect of time on the biting force after 3 months of overdenture insertion regardless the type of support (implant support and root sup-port) there was statistically significant increase in the biting force, after 6 months of overdenture insertion the root supported group showed no statistically significant increase in the biting force. On the other hand the implant supported group showed statistically significant increase in the bit-ing force in 3 month to 6 months follow up interval.

Effect of type of support on the biting force in the two groupsRegarding the effect of type of support on the biting force there was a statistically significant higher biting force recordings for the root sup-ported group immediately after insertion with a mean value of 221.22 N, a mean value of 273.63 N at 3 months and 274.5 N at 6 months after insertion respectively. While the implant sup-ported group the mean values were 163.7857 N, a mean value of 192.1629 N at 3 months and 231.1186 N at 6 months after insertion respectively.

DISCUSSION Generally speaking and from a subjective point of view, all patients who participated in this study appreciated their root supported overdenture and implant supported over-denture. With no doubt, the enhanced sup-port, stability and retention provided by the attachments improved denture functionality, chewing efficiency, and allowed for shorter adaptation periods with minimal post-insertion complaints. This in turn led to increased patient

Table 1: Mean Values and Standard Deviation (SD) of the Biting Force (N) for Both Groups Along the Follow Up Intervals

Implant (gp I) Root (gp II) P-value

Immediate 163.7857±25.56Aa 221.22±29.87Ab

3-month 192.1629±34.89ABa 273.63±33.51Bb

6-month 231.1186±47.04Ba 274.5±20.98Ba

Significant at p ≤ 0.05 Different capital letters indicate significant difference between different follow up periods within the same group. Different small letters indicate significant difference between the two groups within the same follow up period.

< 0.0001

Elkerdawy et al

44 • Vol. 8, No. 3 • May/June 2016

comfort and acceptance of the prosthesis.Regarding the effect of time the results

of this study revealed a statistically signifi-cant increase in biting force at 3 months. This was true for the two treatment situations i.e. root overdenture and implant overdenture. This may be explained by the gradual build-ing up experience and patient adaptation to the new prosthesis. This was in agreement with the results recorded by previous stud-ies.14,15 Were they concluded that regard-less the type of prosthesis, patients usually function with their prosthesis much better after sometime, after they become “used to it” and “to their existence” in their mouths.

Regarding the type of support the bit-

ing force was significantly higher in the root supported over denture than implant sup-ported overdenture immediately after inser-tion, 3 months and 6 months after insertion and this may be attributed to the reduced periodontal support in the implant supported overdenture which may have decreased the threshold level of the mechanoreceptors func-tion16,17 causing changes in the biting force. Also patients with loss of periodontal attach-ment have shown impaired sensory function resulting in reduced control of biting force. These results are consistent with those of another study in which a positive correla-tion between reduced periodontal support and decreased biting force has been shown.18

Graph 1: A Chart Showing Mean Values of the Biting Force (N) Recorded Along the Follow Up Intervals in Both Implant and Root Supported Groups

Elkerdawy et al


CONCLUSION Biting force increased in both root and implant supported overdentures; meanwhile the biting force was higher in the root supported group. In 3 month to 6 months follow up interval the root supported group showed no increase in biting force. On the other hand the implant supported group showed an increase in biting force. ●

Correspondence:

Dr. Nancy Nader Elsherbini

27 Salah salem road,misr elgadida,cairo

Phone: 201005137004

Email: [email protected]

Product Disclosure• Dental implants (Legacy, Spectra system, Implant

direct, USA)

• Cold cure resin (Repair acrylic Garreco. P.O. Box 1258, Herber Springs, USA)

• Locator root attachment kit (Zest Anchors, Inc. Escondido, CA 92029 USA)

• Glass ionomer cement (3M, 275-2SE-03St. Paul, MN 55144-1000, USA)

• Repair acrylic (Garreco. P.O. Box 1258, Herber Springs, USA)

• Loadstar sensors (453 Riverdale Drive, Mountain View, CA 94043, USA)

References:1. Awad MA, Lund JP, Shapiro SH, David L, Esa

K, Antoine C, Andre S, Jocelyne SF. Oral health status and treatment satisfaction with mandibular implant overdentures and conventional dentures: a randomized clinical trial in a senior population. Int J Prosthodont. 2003; 16(4):390-396.

2. Kleinfelder JW, Ludwig K. Maximal bite force in patients with reduced periodontal tissue support with and without splinting. J Periodontol. 2002; 73(10):1184-1187.

3. Trulsson M, Johansson RS. Encoding of amplitude and rate of forces applied to the teeth by human periodontal mechanoreceptive afferents. J Neurophysiol. 1994; 72(4):1734–1744.

4. Trulsson M, Johansson RS, Olsson KA°. Directional sensitivity of human periodontal mechanoreceptive afferents to forces applied to the teeth. J Physiol Lond. 1992; 447:373–389.

5. Trulsson M. Sensory-motor function of human periodontal mechanoreceptors. Journal of Oral Rehabilitation. 2006; 33(4):262–273

6. Dostálová T, Radina P, Seydlová M, Zvárová J, Valenta Z. Overdenture Implants versus Teeth Quality of Life and Objective Therapy Evaluation. Prague Medical Report. 2009;110(4):332–342.

7. Bambara GE. The attachment-retained overdenture. N Y State Dent J. 2004; 70(9):30-3.

8. Feine JS, Carlsson GE, Awad MA, Chehade A, Duncan WJ, Gizani S, Head T, Heydecke G, Lund JP, MacEntee M, et al. The McGill consensus statement on overdentures. Mandibular two-implant overdentures as first choice standard of care for edentulous patients. Gerodontology. 2002; 19(1):3-4.

9. Rismanchian M , Bajoghli F, Mostajeran Z, Fazel A, Eshkevari S. Effect of implants on maximum bite force in edentulous patients. J of Oral Implantology. 2009; 35(4):196-200

10. Gibbs CH, Mahan PE, Lundeen HC, Brehnan K, Walsh EK, Holbrook WB. Occlusal forces during chewing and swallowing as measured by sound transmission. J Prosthet Dent. 1981; 46(4):443-449.

11. Stephanie R T, Greg J D, Jack E L, Alan W E. Quasi-linear viscoelastic behavior of the human periodontal ligament. Journal of Biomechanics. 2002; 35(10):1411–1415

12. Fernandes CP, Glantz PJ, Svensson SA, Bergmark A. A novel sensor for bite force determinations. Dent Mater. 2003;19(2):118- 126.

13. Castroflorio T, Bracco P, Farina D. Surface electromyography in the assessment of jaw elevator muscles. J Oral Rehabil. 2008;35(8):638-645

14. Van Kampen FM, Cune MS, van der Bilt A and Bosman F. The effect of maximum bite force on marginal bone loss in mandibular overdenture treatment: an in vivo study. Clin. Oral Impl. Res. 2005; 16(5):587-593.

15. Van Kampen FM, van der Bilt A, Cune MS and Bosman F. The influence of various attachment types in mandibular implant-retained overdentures on maximum bite force and EMG. J. Dent. Res. 2002;81(8):170-173.

16. Takeuchi N, Yamamoto T. Correlation between periodontal status and biting force in patients with chronic periodontitis during the maintenance phase of theraphy. J Clin Periodontol. 2008;35(3):215-220.

17. Alkan A, Keskiner I, Arici S, Sato S. The effect of periodontitis on biting abilities. J Periodontol. 2006;77(8):1442-1445.

18. Williams WN, Low SB, Cooper WR, Cornell CE. The effect of periodontal bone loss on bite force discrimination. J Periodontol. 1987;58(4):236-239.

Elkerdawy et al

Holtzclaw

Blue Sky Bio, LLC is a FDA registered U.S. manufacturer of quality implants and not affi liated with Nobel Biocare, Straumann AG or Zimmer Dental. SynOcta® is a registered trademark of Straumann AG. NobelReplace® is a registered trademark of Nobel Biocare. Tapered Screw Vent® is a registered trademark of Zimmer Dental.

*activFluor® surface has a modifi ed topography for bone apposition on the implant surface without additional chemical activity.

**U.S. and Canada. Minimum purchase requirement for some countries.

Order online at www.blueskybio.com

CompatibilityInnovation Value

Shipping World Wide

X Cube Surgical Motor with Handpiece - $1,990.00Including 20:1 handpiece, foot control pedal, internal spray nozzle, tube holder, tube clamp, Y-connector and irrigation tube

Bio ❘ Sutures All Sutures 60cm length, 12/boxPolypropylene - $50.00

PGA Fast Resorb - $40.00

PGA - $30.00

Nylon - $20

Silk - $15

Bio ❘ TCP - $58/1ccBeta-Tricalcium Phosphate – available in .25 to 1mm and 1mm to 2mm

Bio ❘One StageStraumannCompatible

Bio ❘ Internal HexZimmerCompatible

Bio ❘ TrilobeNobelCompatible

Bio ❘ZimmerCompatible

Bio ❘NobelCompatible

Bio ❘StraumannCompatible

BlueSkyBio Ad-JIACD Dec.indd 1 10/26/11 12:59 PM

Holtzclaw

Background: Previously published research for a single metropolitan market found that Periodontists fared poorly on the Yelp website in regards to nearly all metrics including aver-age star ratings, number of reviews, review filtering rate, and evaluations by Elite Yelp users. The purpose of the current study was to confirm or refute these findings by expand-ing the data sets to additional metropolitan mar-kets of varying sizes and geographic locations.

Methods: A total of 6,559 Yelp reviews were examined for General Dentists, Endodontists, Pediatric Dentists, Oral Surgeons, Orthodon-tists, and Periodontists in small (Austin, Texas), medium (Seattle, Washington), and large (New York City, New York) metropolitan markets. Numerous review characteristics were evalu-ated including total number of reviews, aver-

age star rating, review filtering rate, and number of reviews by Yelp members with Elite status. Results were compared in multiple ways to deter-mine if statistically significant differences existed.

Results: In all metropolitan markets, Periodon-tists were outperformed by all other dental spe-cialties for all measured Yelp metrics in this study. Furthermore, inter-metropolitan compari-sons of periodontal practices showed no sta-tistically significant differences between them.

Conclusion: The poor performance of Perio-dontists on Yelp may be related to the age profile of patients in the typical periodontal practice. This may result in inadvertent filter-ing of periodontal reviews and subsequently poor performance in multiple other categories.

Comparative Analysis of User Generated Online Yelp Reviews for Periodontal Practices

in Multiple Metropolitan Markets



Abstract

KEY WORDS: Marketing of health services, practice management dental, online input, specialties dental


48 • Vol. 8, No. 3 • May/June 2016

INTRODUCTIONA 2012 study comprising a representative sample of the US population found that 76% of respon-dents indicated that online doctor ratings were important for them when searching for a pro-vider.1 In the United States alone, more than 5 million online reviews have been posted about the healthcare industry on the Yelp website.2 The Yelp website has 165 million unique monthly visitors2 and affords dental practices the oppor-tunity for significant direct to consumer expo-sure. Numerous studies have documented the ability of positive Yelp reviews to improve busi-ness results.3,4 Unfortunately, this has encour-aged many businesses to manipulate their Yelp reviews to achieve financial gains.5 To counter such fraudulent activity, Yelp employs proprietary algorithms to identify and remove (filter) sus-pected illegitimate reviews.3,5 In a previous study, we examined review characteristics and filtering rates of more than 2,000 Austin, TX based den-tal practices on the Yelp website.6 The findings of this study were particularly concerning for the specialty of Periodontics as periodontal practices had high filtering rates, low star ratings, and low total review postings compared to other dental specialties. Although intriguing these results were representative of one single metropolitan area. As such, the purpose of this follow up study was to confirm or refute these findings by comparing them to Yelp metric data from other metropolitan areas of varying sizes and geographic locations.

METHODS AND MATERIALS In the current study, Yelp data for the cities of New York City, New York and Seattle, Washing-

ton were examined and compared to the Austin, Texas data collected from our previous study. Specifically, the search parameters for the cur-rent study were as follows: City – New York City, New York; Category – Dentists; Category – Endodontists; Category – Orthodontists; Cat-egory – Oral Surgeons; Category – Pediatric Dentists; Category – Periodontists. The same category searches were also performed for the city of Seattle, Washington. As in our previous study, the top 10 results were examined for each query. If General Dentists appeared in specialist search queries, they were ignored. Conversely, if specialists appeared in search results for Gen-eral Dentists, the specialist results were ignored.

All results were examined for “recommended” (non-filtered) reviews and non-recommended (“filtered”) reviews. Furthermore, these reviews were also evaluated for star ratings, total review numbers, and Elite Yelp reviews. These results were then compared city to city in pairs using unpaired Student’s T Test with 2 tailed P-values on GraphPad InStat Software (GraphPad Soft-ware, Inc., La Jolla, California). The data for peri-odontal practices in Austin, New York City, and Seattle were then compared to one another in a similar fashion. Finally, the data for all periodontal practices were combined and compared to com-bined data for each dental specialty in the study.

RESULTSA total of 6,559 Yelp reviews for General Den-tists, Endodontists, Oral Surgeons, Orthodon-tists, Pediatric Dentists, and Periodontists in multiple metropolitan markets (Table 1). Com-parisons of Yelp metric data for Periodontists versus other dental specialties in the cities of

Holtzclaw


Averarge Average Total Yelp Number of Dental Metropolitan Yelp Star Yelp Filtering Elite Yelp Specialty Area Rating Review Rate (%) Reviewers

Gen Den Austin 4.81 703 25.35 2.7

Gen Den NYC 4.69 908 26.78 4.1

Gen Den Seattle 4.67 620 25.08 3.3

Gen Den Mean 4.72 743.67 25.74 3.37

Endodontists Austin 4.75 231 30.54 1.0

Endodontists NYC 4.72 247 34.49 0.6

Endodontists Seattle 4.68 202 28.43 0.7

Endodontists Mean 4.72 226.67 31.15 0.77

Orthodontists Austin 4.84 346 47.87 0.6

Orthodontists NYC 4.70 466 46.85 0.3

Orthodontists Seattle 4.82 297 49.44 0.7

Orthodontists Mean 4.79 369.67 48.05 0.53

OMFS Austin 4.47 266 26.82 1.3

OMFS NYC 4.78 616 29.70 3.6

OMFS Seattle 4.46 200 27.69 1.6

OMFS Mean 4.57 360.67 28.07 2.17

Pediatric Den Austin 4.54 349 39.09 0.8

Pediatric Den NYC 4.52 256 50.16 0.4

Pediatric Den Seattle 4.50 329 41.94 0.8

Pediatric Den Mean 4.52 311.33 43.73 0.67

Periodontists Austin 4.19 140 44.47 0.6

Periodontists NYC 3.93 198 52.51 0.4

Periodontists Seattle 4.21 185 50.97 0.3

Periodontists Mean 4.11 174.33 49.32 0.43

Table 1: General Characteristics of Non-Filtered User Generated Yelp Review for all Dental Specialities

Holtzclaw

50 • Vol. 8, No. 3 • May/June 2016

Austin, New York City, and Seattle are pre-sented in Tables 2-4. Combined metropolitan data for Periodontists versus other dental spe-cialties is presented in Table 5. Finally, inter-metropolitan comparisons of Yelp metric data for Periodontists are presented in Table 6.

In examining gross reporting data in Table 1, Periodontists ranked last among all dental spe-cialties for average Yelp star ratings and total number of Yelp reviews. These findings were consistent in all metropolitan areas of this study. For review filtering rates and average number of Elite Yelp reviews, Periodontists ranked last or second to last amongst all dental specialties.

Orthodontists had the highest average star rat-ing followed closely by Endodontists and General Dentists. For total Yelp reviews, General Dentists far exceeded all other dental specialties receiving double the amount of reviews of the next closest competitor and more than 4 times the average number of reviews for Periodontists. In terms of review filtering rates, Periodontists, Orthodontists, and Pediatric Dentists were the most likely to have reviews removed by the Yelp filtering algorithm. Periodontists were nearly twice as likely to have reviews filtered compared to General Dentists, the lowest filtered dental specialty. Concerning Elite Yelp reviews, General Dentists and Oral Surgeons

General Oral Pediatric Yelp Metric Dentists Endodontists Surgery Orthodontists Dentists

Total Yelp P=0.0038 P=0.0048 P=0.0046 P=0.0002 P=0.0001 Reviews VS VS VS VS VS

Average Yelp P=0.0240 P=0.0451 P=0.3362 P=0.0214 P=0.2752 Star Rating SS SS NS SS NS

Yelp Review P=0.0053 P=0.0340 P=0.0079 P=0.6848 P=0.4252 Filtering Rate VS SS VS NS NS

Average # of P=0.0290 P=0.4331 P=0.1964 P=1.0 P=0.6601 Elite Yelp SS NS NS NS NS Reviews

Table 2: Yelp Metric Data of Austin Dental Specialities Compared to Periodontal Practices

Two tailed P values. (SS) statistically significant; (NS) not statistically significant; (VS) very statistically significant; (ES) extremely statistically significant

Holtzclaw


were the most likely to get reviewed by members with Elite Yelp status while Periodontists were the least likely to receive this type of review. Gen-eral Dentists received nearly 8 times more Elite Yelp reviews compared to Periodontists while Oral Surgeons received over 5 times as many.

In evaluating individual metropolitan data with Periodontists being compared to all other den-tal specialties (Tables 2-4), periodontal practices fared poorly in every category. In Austin (Table 2), Periodontists received significantly fewer reviews than all other dental specialties with differences being very statistically significant. Concerning average star rating, Periodontists were the lowest

rated of all dental specialties with only Oral Sur-geons and Pediatric Dentists having ratings that were not statistically significant different. Perio-dontists had the second highest review filtering rate, second only to Orthodontists. Filtering rate differences were statistically significant for all den-tal specialties with the exception of Orthodontists and Pediatric Dentists. Concerning Elite Yelp reviews, Periodontists and Orthodontists received the fewest, but the only difference for Elite reviews of statistical significance was for General Dentists.

In New York City (Table 3), Periodontists received the fewest reviews with only Endodon-tists and Pediatric dentists having differences


Total Yelp P=0.0029 P=0.5924 P=0.0001 P=0.0052 P=0.4059 Reviews VS NS ES VS NS

Average Yelp P=0.029 P=0.0036 P=0.0015 P=0.0039 P=0.0403 Star Rating VS VS VS VS SS


Average # of P=0.0101 P=0.6278 P=0.0016 P=0.7730 P=1.0000 Elite Yelp SS NS VS NS NS Reviews

Table 3: Yelp Metric Data of New York City Dental Specialties Compared to Periodontal Practices


Holtzclaw

52 • Vol. 8, No. 3 • May/June 2016

that were not statistically significant. For average star rating, Periodontists were the lowest rated with results being statistically significant com-pared to all other dental specialties. Concerning filtering rates, Periodontists had the most reviews removed with only Orthodontists and Pediat-ric Dentists having comparative differences that were not statistically significant. The fewest num-ber of Elite reviews were seen for Orthodontists, Periodontists, and Pediatric Dentists respectively. The differences for Elite reviews were not statis-tically significant for these particular specialties.

In Seattle (Table 4), Periodontists received the fewest reviews of all dental specialties, but only General Dentists and Orthodontists had

review differences that were of statistical sig-nificance. Periodontists had the lowest aver-age star rating in Seattle and, once again, only General Dentists and Orthodontists had differ-ences that were of statistical significance. As with the other metropolitan areas in this study, Periodontists, Orthodontists, and Pediatric Den-tists had the highest filtering rates with no differ-ences of statistical significance existing between these specialties. Finally, concerning Elite Yelp reviews, Periodontists received the fewest with only General Dentists and Oral Surgeons having differences of statistical significance.

In evaluating combined data with Periodontists being compared to all other dental specialties


Total Yelp P=0.0012 P=0.7534 P=0.7890 P=0.0028 P=0.0827 Reviews VS NS NS VS NS

Average Yelp P=0.0266 P=0.0529 P=0.3077 P=0.0137 P=0.2721 Star Rating SS NS NS SS NS

Yelp Review P=0.0037 P=0.0163 P=0.0136 P=0.8627 P=0.2796 Filtering Rate VS SS SS NS NS

Average # of P=0.0018 P=0.1449 P=0.0139 P=0.2502 P=0.1825 Elite Yelp VS NS SS NS NS Reviews

Table 4: Yelp Metric Data of Seattle Dental Specialties Compared to Periodontal Practices


Holtzclaw


(Table 5), findings were again consistent with Peri-odontists ranking last in every measured metric with differences of statistical significance for most categories. The only exceptions to these findings where differences of no statistical significance were seen are as follow: a) Total Yelp reviews - Endodontists; b) Average Yelp star rating – None; c) Yelp filtering rate – Orthodontists and Pedi-atric Dentists; d) Elite Yelp Reviews – Endo-dontists, Orthodontists, and Pediatric Dentists.

Finally, in evaluating and compar-ing Yelp metrics for Periodontists alone for the 3 evaluated metropolitan areas of this study (Table 6), no difference of any statisti-cal significance was found in any category.

DISCUSSIONOur previous study was the first of its kind to evaluate characteristics and metric data for online reviews of dental practices.6 The findings of that study were intriguing, particular for Periodontists as it was shown that periodontal practices fared poorly in all measured categories compared to other dental specialties. The findings of the prior study, however, only represented one metropoli-tan area and could be anomalous. To confirm or refute these findings, the current study used a similar data collection format with both expanded and varied data sets. In an effort to reduce popu-lation size bias, small (Austin), medium (Seattle), and large (New York City) metropolitan areas were


Total Yelp P=0.0001 P=0.1589 P=0.0006 P=0.0001 P=0.0011 Reviews ES NS ES ES VS

Average Yelp P=0.0001 P=0.0001 P=0.0024 P=0.0001 P=0.0117 Star Rating ES ES VS ES SS

Yelp Review P=0.0001 P=0.0001 P=0.0001 P=0.7884 P=0.2076 Filtering Rate ES ES ES NS NS

Average # of P=0.0001 P=0.1470 P=0.0001 P=0.6378 P=0.3040 Elite Yelp ES NS ES NS NS Reviews

Table 5: Combined City Yelp Metric Data of Periodontal Practices Compared to Other Dental Specialties


Holtzclaw

54 • Vol. 8, No. 3 • May/June 2016

evaluated. Furthermore, these cities with separa-tion distances of anywhere from 1,750 to 2,900 miles were selected to reduce both geographic and cultural bias. The data presented in this study confirms that in all markets, Periodontists receive fewer Yelp reviews and are rated lower than all other dental specialties. Furthermore, periodon-tal practices are the most likely to have reviews removed by Yelp’s filtering algorithm and the least likely to receive evaluations by members with Elite Yelp status. These findings were consistent in all metropolitan markets no matter how the data was evaluated. This suggests that the findings of the prior study are not anomalous. Further bolster-ing these findings is the fact that the results of the current study were again consistent with the prior study in regards to nearly every measured Yelp metric for all other evaluated dental special-

ties in all metropolitan markets. Concerning the specialty of Periodontics, these results stimulate a number of questions. First and foremost, why are periodontal practices consistently receiving fewer reviews and lower star ratings compared to other dental specialties? Second, why are periodontal practices the least likely to be reviewed by Yelp members with Elite status and is this important? Finally, why are periodontal reviews the most likely to be removed by the Yelp filtering algorithm?

One possible answer to these questions may lie in the age profile of patients at periodon-tal practices. According to a recently published update to the Prevalence of Periodontitis in the United States: NHANES 2009-2012 study, the highest prevalence of periodontal disease was seen in people aged 50 or more.7 Accord-ingly, one would expect patients of a periodon-

Average Total Yelp Average Number Metropolitan Yelp Star Yelp Filtering of Elite Yelp Area Rating Reviews Rate Reviewers

Austin vs New York City P=0.4467 P=0.7825 P=0.3574 P=0.669 NS NS NS NS

Austin vs Seattle P=0.9470 P=0.2055 P=0.4734 P=0.4313 NS NS NS NS

Seattle vs New York City P=0.3445 P=0.5364 P=0.8799 P=0.7730 NS NS NS NS

Table 6: Yelp Metric Data for Periodontists Compared Intra-City

Unpaired student’s T-test: two tailed P values. (SS) statistically significant; (NS) not statistically significant; (VS) very statistically significant; (ES) extremely statistically significant

Holtzclaw


tal practice to be predominantly represented by this same age cohort. Although no know studies exist documenting the age make-up of the typical periodontal practice, analysis of the author’s per-sonal private periodontal practice in Austin, Texas revealed that 61.4% of the patients in the practice were aged 51 or older. The preponderance of older patients in periodontal practices may have a large influence on the poor performance of Perio-dontists on the Yelp website compared to other dental specialties. Concerning the high filtering rate of periodontal reviews on Yelp, people aged 55 and older represent the smallest percentage of Yelp users.2 While people of this age cohort are the smallest minority of Yelp users, they comprise the majority of people who are treated in the typi-cal periodontal practice. Should these patients choose to write a review for their Periodontist on Yelp, statistics indicate that the majority of these patients will not have an established Yelp account and will need to join the website in order to write an evaluation.6 As a new Yelp member, these people will have minimal friends on the Yelp social network and will not have a history of published reviews. Previously published research (Luca, our prior study) indicates that these reviews would be at extremely high risk for filtering.3,6 A higher number of filtered reviews would, in turn, result in a lower number of “recommended” reviews which are the only reviews considered when cal-culating Yelp star ratings. While a higher num-ber of filtered reviews may negatively affect Yelp star ratings, an older age profile may also do the same. A number of previously published stud-ies have shown age to be negatively associated with consumer propensities to brand innovative-ness and variety.8,9 Additionally, increasing age has been associated with heightened perceived

risk when choosing brand alternatives.10 As peri-odontal practices are largely referral based, a large percentage of these patients come from general dental practices.11 Because these Gen-eral Dentists are their primary provider of dental care, referred patients may consider their Gen-eral Dentist as their trusted “brand” of choice for dental services. It is well documented that older customers develop brand loyalty over time and have less desire to switch providers of their trusted brands and services.12,13 These older patients may interpret a referral to the periodon-tist as utilizing an unfamiliar “brand” of dentistry to whom they have no established loyalty and, thus, would be less likely to leave a positive review or any review for that matter. Even if they do leave a review, there is nearly a 50% chance it will be fil-tered and removed by Yelp according to the find-ings of the current study. Although other dental specialties also rely on patient referrals from Gen-eral Dentists, these patients tend to be of younger age cohorts.14,15 Research evaluating consumer purchasing patterns of younger patients indicates that they are less brand loyal, more likely to utilize alternative products, and would therefore be less averse to referrals of outside providers.16 This is evident when examining Yelp users with “Elite” status. Although Yelp does not provide specifics regarding the selection process for the assign-ment of elite status to its members, studies evalu-ating the profiles of these select members indicate that they have extremely high social connectivity.17 Recent publications from the Pew Research Cen-ter indicate that the most socially connected users are under the age of 30.18 These findings are sup-ported by the current study which found that the majority of Elite Yelp users were associated with younger age profiles. Furthermore, the current

Holtzclaw

56 • Vol. 8, No. 3 • May/June 2016

study found that Elite Yelp users tended to write reviews on dental services associated with early adulthood such as third molar removal, exams, cleanings, and bleaching. Accordingly, the dental specialties of Oral Surgery and General Dentistry received significantly more reviews from Elite Yelp users than all other dental spe-cialties in the current study. The high number of reviews from Elite Yelp users may benefit these specialties as research has shown that Elite users are considered “opinion leaders” on Yelp who publish up to 7 times more reviews than typical Yelp users, have fewer reviews filtered, and have more friends on the Yelp social net-work.19 As periodontists were the least likely to receive Elite Yelp reviews, this may put peri-odontal practices at a disadvantage in receiv-ing the benefits associated with such reviews including increased exposure to a larger social network of potential customers and fewer reviews removed by the Yelp filtering algorithm.

CONCLUSIONThe results of our current and prior study show that Periodontists may be at an inherent disad-vantage when using the Yelp website due to the advanced age profile of periodontal patients. Findings of low average star ratings, fewer reviews, high filtering rates, and minimal access by Elite Yelp members were consistent for peri-odontal practices in multiple metropolitan mar-kets. These findings suggest that Periodontists should carefully evaluate their social media strat-egies and may want to shift their advertising dollars to venues that do not inadvertently discrim-inate against the age profile of their patients. ●

Correspondence:Dan Holtzclaw, DDS, MS11921 Palisades PkwyAustin, TX [email protected]

Conflicts of InterestThe authors report no conflicts of interest with anything mentioned in this article.

References1. Hanauer DA, Zheng K, Singer DC, Gebremariam

A, Davis MM. Public awareness, perception, and use of online physician rating sites. JAMA 2014;311:734-735.

2. Yelp. An Introduction to Yelp Metrics as of September 30, 2015. Available at http://www.ylep.com/factsheet. Accessed December 28, 2015.

3. Luca M, Zervas G. Fake It Till You Make It: Reputation, Competition, and Yelp Review Fraud. Harvard Business School NOM Unit Working Paper; 2013:1-35.

4. Anderson M, Magruder J. Learning From the Crowd: Recognition Discontinuity Estimates of the Effects of an Online Review Database. Economic Journal 2012;122:957-989.

5. Rahman M, Carbunar B. Ballesteros J. Turning the Tide: Curbing Deceptive Yelp Behav-iors. Conference Paper, April 2014; DOI 10.1137/1.9781611973440.28.

6. Holtzclaw, D. An Analysis of Online Review Characteristics and Filtering Rates for User Generated Yelp Evaluations of Periodontal Practices in a Major Metropolitan Market. Submitted to J Periodontol.

7. Eke PI, Dye BA, Wei L, Slade GD, Thornton-Evans GO, et al. Update on Prevalence of Periodontitis in Adults in the United States: NHANES 2009 to 2012. J Periodontol 2015;86:611-22.

8. Mather, M. The allure of the allignable: Younger an d older adults’ flase memories of choice features. J Exp Psychol 2005;134:38-51.

9. Lambert-Pandraud R, Laurent G. Why do older consumers buy older brands? The role of attachment and declining innovativeness. J Market 2010;74:97-113.

10. Yeung R, Moriss J. An empirical study of the impact of consumer perceived risk on purchase likelihood: A modelling approach. Int J Consumer Stud 2006;30:294-305.

11. Lee JH, Bennett DE, Richards PS, Inglehart MR. Periodontal referral patterns of general dentists: lessons for dental education. J Dent Ed 2009;73:199-210.

12. Yoon C, Cole C, Lee M. Consumer decision making and aging: Current knowledge and future directions. J Consumer Psych 2009;19:2-16.

13. Patterson P. Demographic corrleates of loyalty in a service context. J Services Marketing 2007;21:112-121.

14. Saad AY, Clem WH. An evaluation of etiologic factors in 382 patients treated in a postgraduate endodontic program. Oral Surg Oral Med Oral Pathol 1988;65:91-93.

15. Alvira-González J, Gay-Escoda C. Compliance of postoperative instructions following the surgi-cal extraction of impacted lower third molars: a randomized clinical trial. Med Oral Patol Oral Cir Bucal 2015;20:224-230.

16. Wood L. Dimensions of brand purchasing be-havior: Consumers in the 18-24 age group. J Consumer Behaviour 2004;4:9-24.

17. Crain K, Heh K, Winston J. An analysis of the elite users on yelp.com. Available at: http://snap.stanford.edu/class/cs224w-2014/projects2014/cs224w-32-final.pdf. Accessed on Jan 10, 2016.

18. Duggan M. The demographics of social media users. Available at: http://www.pewinternet.org/2015/08/19/the-demographics-of-social-media-users. Accessed on Jan 10, 2016.

19. Tucker T. Online word of mouth: Characteristics of Yelp.com Reviews. Elon J Undergrad Res Com 2011;2(1):37-42.

Holtzclaw

The Journal of Implant & Advanced Clinical Dentistry • XX

Holtzclaw

Holtzclaw

www.dentalxp.com

Upgrade Today!

JIACD510

Valid ti l l 12/31/10

Be part of the # 1 website on Google Search for online dental education.

FREESUBSCRIPTION

Use coupon above to upgrade your account to premium.

Holtzclaw

Background: User generated online reviews of businesses have increased dramatically dur-ing the past decade. The ability of these reviews to positively influence business revenues has resulted in occasional fraudulent review manipu-lation. To combat this, online review websites have begun to employ computer algorithms that identify and remove suspected fraudulent reviews. The purpose of this study was to ana-lyze characteristics and filtering rates for user generated Yelp evaluations of dental practices with a specific focus on periodontal practices.

Methods: A total of 2,035 Yelp reviews were examined for General Dentists, Endodontists, Pediatric Dentists, Oral Surgeons, Orthodon-tists, and Periodontists in the Austin, Texas metropolitan market. A variety of review char-acteristics were evaluated for both filtered and non-filtered Yelp evaluations and filter-ing rates were determined. Additionally, these data were compared and contrasted regarding Periodontists and all other dental specialties.Results: User generated Yelp reviews for dental practices had higher overall average star ratings

compared to other businesses. Conversely, den-tal practices had dramatically higher review filter-ing rates compared to other businesses on Yelp. When the specialty of Periodontics was specifi-cally compared to other dental specialties, a num-ber of differences were noted. First and foremost, periodontal practices received significantly fewer Yelp reviews than all other dental specialties. Sec-ond, periodontal practices were the lowest rated of all dental specialties. Third, periodontal prac-tices were the least likely to be reviewed by “Elite” Yelp members. Finally, and possibly most impor-tantly, nearly half of Yelp reviews submitted for periodontal practices were filtered and removed.

Conclusion: The data presented in this study indicate that periodontal practices lag behind their dental specialty counterparts in nearly all aspects of Yelp metric data. Furthermore, patients of periodontal practices may experience increased difficulty posting non-filtered Yelp reviews in com-parison to reviews they may post for other den-tal practices or businesses. This data should be considered carefully in the marketing and social media strategies of periodontal practices.

Analysis of Online Review Characteristics and Filtering Rates for User Generated Yelp Evaluations of Periodontal Practices in a Major Metropolitan Market



Abstract

KEY WORDS: Marketing of health services, practice management dental, online input, specialties dental


60 • Vol. 8, No. 3 • May/June 2016

Holtzclaw

Dental Specialty Total Number of Yelp Reviews Average Yelp Star Rating

General Dentistry 703 4.81

Endodontics 231 4.75

Oral Surgery 266 4.48

Orthodontics 346 4.84

Pediatric Dentistry 349 4.54

Periodontics 140 4.19

INTRODUCTIONOver the past decade, user generated online reviews have become an increasingly important tool for consumers when making purchasing deci-sions for goods and services.1,2 This is undeni-ably evident in the fact that more than 100 million reviews currently exist on websites such as Yelp! And TripAdvisor.3,4 A number of studies indicate that online reviews may have a direct influence on product sales5,6 and that some companies attempt to manipulate these reviews for financial gain.7,8 To combat such behaviors in an effort to maintain the integrity of their websites, companies such as Yelp have employed sophisticated computer algo-rithms to identify and remove suspected fraudulent reviews.3,9 While a significant amount of research has been published analyzing online review char-acteristics and filtering rates of restaurants and hotels,2,3,10,11 virtually nothing has been published regarding the same for dentists. Accordingly, the purpose of this article is to examine online review characteristics and filtering rates for the dental

industry. Moreover, this data is further examined with specific emphasis on the specialty of Periodontics.

MATERIALS AND METHODSFor the purpose of this study, the online review website Yelp was examined. Specifically, search parameters were as follows: City – Austin; Cat-egory – Dentists; Category – Endodontists; Cat-egory – Orthodontists; Category – Oral Surgery; Category – Pediatric Dentists; and Category – Periodontists. For each query, the top 10 results were examined. In cases where general dentists appeared in query results for dental specialists, the General Dentist listings were ignored. Like-wise, if dental specialists appeared in query results for general dentists, the dental specialist listings were ignored. Each result was examined for both “recommended” (non-filtered) and “not-recom-mended” (filtered) reviews. Each of these reviews was then further examined for star ratings, the number of reviews posted by each reviewer, the number of friends of each reviewer, whether or not

Table 1: General Characteristics of User Generated Yelp Reviews of Dental Practices In Austin, Texas


Holtzclaw

Average Average Percentage Averarge Review Average Number of Number of of Yelp Number of Dental Filtering Yelp Star Reviews by Friends of Users with Elite Yelp Specialty Rate Rating Yelp User Yelp User Profile Pic Reviews

General 25.35 4.80 2.06 0.45 11.9 0 Dentistry

Endodontics 30.53 4.28 2.37 0.89 17.9 0

Oral 26.8 4.63 4.27 1.50 9.7 0 Surgery

Orthodontics 47.87 4.65 2.39 0.77 19.7 0

Pediactric 39.10 4.35 2.22 1.07 35.1 0 Dentistry

Periodontics 44.47 4.69 2.48 0.49 19.9 0

the reviewer had a profile picture, and whether or not reviewers were of “Elite” Yelp status. These results were then compared in pairs using unpaired Student’s T test on GraphPad InStat Software (GraphPad Software, Inc, La Jolla, California).

RESULTSFor the 60 evaluated dental practices in this study, a total of 2,035 Yelp reviews were exam-ined. The largest number of reviews were for General Dentists, followed by Pediatric Dentists, Orthodontists, Oral Surgeons, Endodontists, and Periodontists. A breakdown of reviews by den-tal specialty is listed in Table 1. The number of

reviews left for General Dentists was dramatically higher than all other dental specialties and was statistically significant when individually compared to each group. The reviewer star rating for den-tists evaluated in this study ranged from 4.19 to 4.84 with Periodontists receiving the lowest aver-age star rating and Orthodontists receiving the highest average star rating. In general, the aver-age Yelp star rating for all dentists was 4.59 stars.

Data for filtered reviews is presented in Table 2. Compared to non-filtered Yelp reviews, there were substantial differences in all metric categories for filtered Yelp reviews with one notable exception: star ratings. Filtered Yelp reviews in this study had

Table 2: Characteristics of Filtered (Non-recommended) User Generated Yelp Reviews of Dental Practices in Austin, Texas

62 • Vol. 8, No. 3 • May/June 2016

Holtzclaw

an average rating of 4.57 stars while those of non-filtered reviews had an average of 4.59 stars. In comparing filtered reviews for all dental specialties, there were no statistically significant differences in measured metrics. However, when these filtered reviews were compared to non-filtered reviews for all dental specialties, very significant differ-ences were noted. Across all dental specialties, the average number of reviewer’s friends seen with filtered reviews was 0.86 compared to 24.35 friends for non-filtered reviews. The average num-ber of reviewer published evaluations for filtered reviews was 2.63 reviews compared to an average of 37.16 reviews for non-filtered reviews. In evalu-

ating the percentage of Yelp reviewers with pro-file pictures for filtered versus non-filtered reviews, the difference was very statistically significant. While 74.03% of reviewer’s had profile pictures in non-filtered reviews, only 19.02% of reviewers in filtered reviews had profile pictures. Finally, the number of Elite Yelp reviewers was significantly dif-ferent for filtered and non-filtered reviews. While there were zero Elite Yelp profiles seen with fil-tered reviews, a total of 70 non-filtered reviews were provided by persons with Elite Yelp profiles.

Data concerning the reviewers that posted the Yelp reviews examined in this study are shown in Table 3. Because Yelp considers filtered reviews to

Average Average Percentage Averarge Average Number of Number of of Yelp Number of Dental Yelp Star Reviews by Friends of Users with Elite Yelp Specialty Rating Yelp User Yelp User Profile Pic Reviews

General 4.81 43.60 38.68 92.5 2.7 Dentistry

Endodontics 4.75 38.11 25.85 70.7 1.0

Oral 4.48 45.63 25.27 67.8 1.3 Surgery

Orthodontics 4.84 21.48 11.20 73.7 0.6

Pediactric 4.54 34.78 26.78 73.5 0.8 Dentistry

Periodontics 4.19 39.35 18.32 66.0 0.6

Table 3: Characteristics of Filtered (Recommended) User Generated Yelp Reviews of Dental Practices in Austin, Texas


Holtzclaw

be potentially fraudulent, only data for non-filtered reviews were considered for evaluating the profiles of a typical Yelp user in this study. On average, the typical Yelp user providing a review for den-tal services had 24.35 Yelp friends, posted 37.12 reviews, and was 74.03% likely to have a profile picture. While there were some noted differences between dental specialties concerning the char-acteristics of their typical Yelp reviewers, the most dramatic differences were noted with Elite Yelp reviewers. General Dentists consistently had the most Elite Yelp reviews with statistically significant differences compared to all other dental specialties.

Data for Yelp reviews of Periodontal practices

compared to those of other dental specialties are presented in Table 4. Periodontal practices had significantly fewer total Yelp reviews than all other dental specialties. General Dentists had the most Yelp reviews of all dental specialties and had more than five times the total number of Yelp reviews of Periodontists. Even Endodontists, who had the second fewest total number of Yelp reviews, still had 65% more total Yelp reviews than Periodon-tists. In terms of star ratings, Periodontal practices had the lowest average rating with 4.19 stars while Orthodontists had the highest average rating of 4.84 stars. The lower difference in star ratings for Periodontists was statistically significant compared


Total Yelp P=0.0038 P=0.0048 P=0.0046 P=0.0002 P=0.0001 Reviews VS VS VS VS VS

Average Yelp P=0.024 P=0.0451 P=0.3362 P=0.0214 P=0.2752 Star Rating SS SS NS SS NS


Average # of P=0.0290 P=0.4331 P=0.1964 P=1.0 P=0.6601 Elite Yelp SS NS NS NS NS Reviews

Table 4: Yelp Metric Data of Other Dental Specialties Compared to Periodontal Practices

Two tailed P values. (SS) statistically significant; (NS) not statistically significant; (VS) very statistically significant

64 • Vol. 8, No. 3 • May/June 2016

Holtzclaw

to General Dentists, Endodontists, and Ortho-dontists. Concerning review filtering rates, Perio-dontists ranked towards the bottom of all dental specialties with only Orthodontists and Pediatric Dentists faring slightly worse. Finally, Periodon-tists were the dental specialty least likely to receive reviews by Yelp members with designated “Elite” status. While Oral Surgeons and Endodontists were twice as likely to receive Elite Yelp reviews compared to Periodontists, General Dentists were nearly five times as likely to receive Elite Yelp reviews.

DISCUSSIONThe explosive growth of online social media has empowered individual users to share information to mass audiences with the simple click of a but-ton. Over the past five years, this phenomenon has had a tremendous effect on consumer purchasing decisions for goods and services and represents a significant change from traditional “word of mouth” sharing of information.6,10,11 With more than 80 mil-lion posted reviews that are seen by over 165 mil-lion unique monthly visitors,12 Yelp has proven to be one of the most widely used review sites on the internet. Health related business evaluations such as those for medicine and dentistry account for 6% of Yelp reviews.12 Over 50% of Yelp users are aged 35 or older with a college degree and earnings of $60,000+ per year which makes Yelp a very attrac-tive platform for advertising dental practices.12

Studies have shown Yelp’s ability to positively influence business revenue. For example, online consumer review studies of the restaurant industry show that an extra half star rating on Yelp causes restaurants to sell out 19% more frequently13 while studies of hotel ratings show a one star improve-ment on Yelp may increase revenue up to 9%.5

These positive economic benefits have not gone

unnoticed by dentists as an increasing number of practices now advertise on Yelp. Furthermore, the positive economic incentives of online reviews has also led to an increase in fraudulent review activ-ity.9 To fight such fraudulent activity, companies such as Yelp employ proprietary computer algo-rithms to identify and remove potentially illegitimate reviews.3,9 The sophistication of Yelp filtering algo-rithms and the persistence of fraudulent review-ers is apparent in the fact that the percentage of reviews deemed illegitimate by Yelp has more than tripled to over 20% over the past ten years.3

In evaluating the top 10 Yelp rated General Den-tists, Endodontists, Oral Surgeons, Orthodontists, Pediatric Dentists, and Periodontists in Austin, TX, some interesting trends were observed. First and foremost, the data presented in this study indicates that General Dentists are the dental professionals most likely to be reviewed on Yelp with all other den-tal specialties, particularly Periodontics, lagging far behind. The total number of online reviews a dental business receives has importance as demonstrated by Grabner-Krauter and Waiguny in 2015 whose study showed that top rated dentists received up to ten times more reviews compared to the bottom 10% of rated dentists.14 In terms of star ratings, all dental categories had extremely high average ratings with a range of 4.19 to 4.84 stars. With an overall average rating of 4.59 stars, dental prac-tices rated higher than most other businesses on Yelp. While 87% of dental practices in this study achieved Yelp ratings of 4 stars or higher, only 67% of other businesses on Yelp rate 4 stars or higher.12

Although dental practices had higher overall star ratings compared to other Yelp reviewed busi-nesses, they also had a higher review filter rate. Review filtering is a strategy employed by Yelp whereby proprietary algorithms are utilized to iden-


Holtzclaw

tify and remove reviews suspected of being fraudu-lent. Previous studies have noted that up to 25% of reviews on Yelp may be fraudulent9 and that Yelp filtering algorithms remove up to 22% of all posted reviews.12 Overall, dental practices in this study had a review filter rate of 35.69%. This is more than double the 16% Yelp review filtering rate for restaurants as reported by Luca and colleagues.3 When broken down further and examined more closely, the filtering rate for certain dental spe-cialties is even more dramatic with orthodontic, periodontal, and pediatric dental practices having 47.86%, 44.47%, and 39.01% of reviews respec-tively filtered. While these dental specialties were plagued by abnormally high review filtering rates, the reasons for Yelp’s flagging of these particular reviews may be quite different. Concerning orth-odontic and pediatric dental practices, the high review filter rate may be due to the fact that many of the reviews for these specialists are written by parents for treatment actually received by their children. Yelp review guidelines state that reviews should be “first hand consumer experiences.”15 Many orthodontic and pediatric dental reviews fil-tered by Yelp appeared to be parents writing about the experiences that their children had with the dentist. Because the verbiage in these reviews technically describes experiences for a third party (i.e. the child), it is possible that Yelp filtering algo-rithms may recognize these reviews as violating published Yelp review guidelines and thus filter them as being inappropriate. Concerning peri-odontal practices, the abnormally high filtering rate for reviews on Yelp may be due to completely dif-ferent reasons. Published studies have shown that the average age of patients treated for periodon-tal disease is over the age of fifty.16 According to data published by Yelp, less than 20% of its users

meet this age characteristic and people aged 55+ make up the smallest age cohort on the review website.12 As the majority of patients in periodon-tal practices are of an age group that is amongst the most under-represented by Yelp users, it is logical to assume that the majority of periodontal patients do not have Yelp accounts. Accordingly, if a periodontal patient joins Yelp to write a review for their Periodontist, there is a high likelihood that the patient will have few established friends on Yelp and will be writing their first Yelp review. The data presented in this study for characteristics of filtered Yelp reviews indicate that such a review would be at high risk for filtering. These findings are supported by the findings of Luca and Zervas’ 2013 evaluation of 316,415 Yelp reviews of 3,625 Boston metropolitan restaurants.3 In this study, fil-tered Yelp reviews were predominantly from users that had written few prior reviews, had few friends on Yelp’s social network, and were less likely to have a profile photo associated with their account. While some reviews flagged by Yelp’s filtering algorithm may indeed be fraudulent, the program is not perfect and sometimes affects legitimate reviews.3,9 The results of the current study indi-cate that certain dental specialties with very young or older patient populations may be at higher risk for having legitimate online reviews flagged as “not recommended” by the Yelp filtering algorithm.

Because periodontal practices inherently have older patient populations compared to other den-tal specialties, they may be at a competitive dis-advantage when seeking Yelp reviews from their patients. This is evident in the significantly high filtering rate for Yelp reviews of periodontal prac-tices, the lagging total number of Yelp reviews, and the minimal number of “Elite” Yelp reviewers. While these suboptimal results for Yelp metric

66 • Vol. 8, No. 3 • May/June 2016

Holtzclaw

data of periodontal practices may potentially be explained by older patient populations, the lower average star rating of periodontal practices com-pared to all other dental specialties is concerning as this is not related to an older patient population.

CONCLUSIONWith 165 million unique monthly users who have posted a total of more than 5 million online reviews for the healthcare industry,11 Yelp is becoming an important component for many dental prac-tice marketing strategies. To utilize this platform effectively, dental practices should evaluate data concerning the publication of these reviews. The data presented in this study indicate that consumers may have increased difficulty post-ing non-filtered Yelp reviews for dental practices in comparison to reviews posted for other busi-nesses. Moreover, Yelp reviews for certain den-tal specialties with older patient populations such as Periodontics have dramatically higher filter-

ing rates. As such, it may behoove periodontal practices to consider other options in addition to Yelp for their social media marketing strategies. While the findings of this study are intriguing, they are only representative of a single metropolitan area in one particular area of the country. To cor-roborate or refute these findings, the same meth-odology should be employed to evaluate other metropolitan areas in different geographic locations around the United States. Furthermore, the addi-tion of more metropolitan areas to this study will also increase the ‘n’ of the review analyses which will strengthen the validity of the evaluated data. ●

Correspondence:

Dan Holtzclaw, DDS, MS

11921 Palisades Pkwy

Austin, TX 78732

[email protected]

Conflicts of InterestThe author reports no conflicts of interest with anything mentioned in this article.

References1. Sridhar S, Srinivasan R. Social Influence Ef-

fects in Online Product Ratings. J Marketing 2012;76:70-88.

2. Schuckert M, Liu X, Law R. Insights Into Suspicious Online Ratings: Direct Evidence from TripAdvisor. Asia Pacific J of Tourism Res 2015;Ahead of print:1-14.

3. Luca M, Zervas G. Fake It Till You Make It: Reputation, Competition, and Yelp Review Fraud. Harvard Business School NOM Unit Working Paper; 2013:1-35.

4. Mayzlin D. Promotional Chat on the Internet. Marketing Science 2006;25:155-163.

5. Luca M. Reviews, Reputation, and Revenue: The Case of Yelp.com. Harvard Business School NOM Unit Working Paper;2011:12-16.

6. Chevalier J, Mayzlin D. The Effect of Word of Mouth on Sales: Online Book Reviews. J Market-ing Res 2006;43:345-354.

7. Hu N, Bose I, Koh N, Liu L. Manipulation of Online Reviews: An Analysis of Ratings, Readability, and Sentiments. Decision Support Systems 2012;52:674-84.

8. Gurun U, Butler A. Don’t Believe the Hype: Local Media Slant, Local Advertising, and Firm Value. J Finance 2012;67:561-98.

9. Rahman M, Carbunar B. Ballesteros J. Turning the Tide: Curbing Deceptive Yelp Behav-iors. Conference Paper, April 2014; DOI 10.1137/1.9781611973440.28.

10. Berezina K, Bigihan A, Cobanoglu C, Okumus F. Understanding Satisfied and Dissatisfied Hotel Customers: Text Mining of Online Hotel Reviews. J Hospitality Marketing Management 2015;00:1-24.

11. Levy S, Wenjing D, Boo S. An Analysis of One-Star Online Reviews and Responses in the Washington DC Lodging Market. Cornell Hospitality Quarterly 2013;54:49-63.

12. Yelp. An Introduction to Yelp Metrics as of September 30, 2015. Available at: http://www.ylep.com/factsheet. Accessed on December 18, 2015.

13. Anderson M, Magruder J. Learning From the Crowd: Recognition Discontinuity Estimates of the Effects of an Online Review Database. Economic Journal 2012;122:957-989.

14. Grabner-Krauter S, Waiguny M. Insights Into the Impact of Online Physician Reviews on Patients’ Decision Making: Randomized Experiment. J Med Internet Res 2015;17:1-29.

15. Yelp. Content Guidelines: Review Guidelines. Available at: http://www.yelp.com/guidelines. Accessed on December 15, 2015.

16. Eke PI, Dye BA, Wei L, Slade GD, Thornton-Evans GO, et al. Update on Prevalence of Periodontitis in Adults in the United States: NHANES 2009 to 2012. J Periodontol 2015;86:611-622.

The Journal of Implant & Advanced Clinical Dentistry • XX

Holtzclaw

IntroducIng

Less pain for your patients.1

Less chair side time for you.1

Mucograft® is a pure and highly biocompatible porcine collagen matrix. The spongious nature of Mucograft® favors early vascularization and integration of the soft tissues. It degrades naturally, without device related inflammation for optimal soft tissue regeneration. Mucograft® collagen matrix provides many clinical benefits:

For your patients...

Patients treated with Mucograft® require 5x less Ibuprofen than

those treated with a connective tissue graft1

Patients treated with Mucograft® are equally satisfied with esthetic outcomes when compared to connective tissue grafts2

For you...

Surgical procedures with Mucograft® are 16 minutes shorter in duration on average when compared to those involving connective tissue grafts1

Mucograft® is an effective alternative to autologous grafts3, is ready to use and does not require several minutes of washing prior to surgery

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

Mucograft® is indicated for guided tissue regeneration procedures in periodontal and recession defects, alveolar ridge reconstruction for prosthetic treatment, localized ridge augmentation for later implantation and covering of implants placed in immediate or delayed extraction sockets. For full prescribing information, visit www.osteohealth.com

Ask about our limited time, introductory special!

24 JIACDThe Journal of Implant & Advanced Clinical Dentistry

October 2008 Review | Oral Implications of Cancer Cheomotherapy October 2008October 2008

ADVERTISE WITHADVERTISEADVERTISE WITHADVERTISEADVERTISE WITH

TODAY!

WWW.JIACD.COM

Using revolutionary online technology, JIACD provides its

readers with an experience that is simply not available with traditional

hard copy paper journals.

Reach more customers with the dental profession’s fi rst truly interactive

paperless journal!

simply not available with traditional

Titanium Mesh Ridge Augmentation for Dental Implant Placement · Implant Placement: A Case Report...

Documents

Transcript of Titanium Mesh Ridge Augmentation for Dental Implant Placement · Implant Placement: A Case Report...