Maxillary Sinus Augmentation:

Transcription

1 Earn 4 CE credits This course was written for dentists, dental hygienists, and assistants. Maxillary Sinus Augmentation: Fixed Restorations in the Compromised Posterior Maxilla A Peer-Reviewed Publication Written by Stephen S. Wallace, DDS PennWell is an ADA CERP recognized provider ADA CERP is a service of the American Dental Association to assist dental professionals in identifying quality providers of continuing dental education. ADA CERP does not approve or endorse individual courses or instructors, nor does it imply acceptance of credit hours by boards of dentistry. PennWell is an ADA CERP Recognized Provider Concerns of complaints about a CE provider may be directed to the provider or to ADA CERP at Go Green, Go Online to take your course This course has been made possible through an unrestricted educational grant. The cost of this CE course is $59.00 for 4 CE credits. Cancellation/Refund Policy: Any participant who is not 100% satisfied with this course can request a full refund by contacting PennWell in writing.

2 Educational Objectives Upon completion of this course, the clinician will be able to do the following: 1. Identify appropriate graft materials for sinus surgery. 2. Compare implant survival rates pertaining to membrane placement. 3. Select implants based on surface texture. Abstract Lateral window sinus elevation is a preprosthetic procedure that can increase the success rate for posterior maxillary implants. An evidence-based decision process is required so that appropriate decisions can be made that will lead to the most positive patient outcomes. Introduction Implant dentistry has dramatically changed the way we approach our fully and partially edentulous patients. A technique that was introduced to specifically address the edentulous mandible has evolved to encompass therapy to the edentulous maxilla, the partially edentulous patient and finally, to the patient missing a single tooth. 1 Bone loss following tooth extraction and/or periodontal disease can complicate the placement of root-form implants due to a lack of sufficient height or width of residual bone. This can be overcome with ridge augmentation procedures that can restore the lost bone volume. The posterior maxilla may present an additional obstruction to implant placement due to pneumatization (increasing size) of the maxillary sinus. Some patients possess limited crestal bone height in the posterior maxilla even when teeth are present and it is not uncommon for the sinuses to pneumatize further after the extraction of the posterior teeth. Pneumatization alone, even without any additional loss of crestal bone due to periodontal disease, may be sufficient to prevent the uncomplicated placement of even short implants in the posterior maxilla without prior sinus elevation surgery. Figure 1 and Figure 2 give an example of the change in bone height that can be achieved with the lateral window sinus elevation technique. The surgical technique of maxillary sinus floor elevation was first published by Boyne in In the 25 years since then, a host of surgical procedures have been developed to correct the bone deficiency created by sinus pneumatization. They are all forms of sinus elevation surgery and the techniques include variations of Boyne s lateral window antrostomy, the osteotome sinus floor elevation, crestal core elevation and the localized management of the sinus floor. 3 5 Recent evidence-based literature reviews by Wallace et al. and Del Fabbro et al. have reported remarkable levels of success for all of these techniques. 6,7 In light of the improved prosthetic options that maxillary posterior Figure 1. Posterior maxilla with pneumatized sinus and minimal crestal bone height. Crestal bone height in molar region is 3-4 mm. Figure 2. Maxillary sinus grafted with Bio-Oss xenograft prior to the placement of implants. Crestal bone height is now 15 mm. Figure 3. Full thickness flap elevated and lateral window outlined Figure 4. Window outlined with #8 diamond bur Figure 5. Outline completed with sinus membrane visible implant placement can make available to our patients, it is important for both surgical and restorative dentists to be aware of this therapeutic approach and know how best to maximize patient outcomes using a decision-making process whereby the proper choices can lead to an 2

3 Figure 6. Membrane elevation initiated with Hu-Friedy Kramer #3 curette Figure 7. Membrane elevation completed up the medial wall of the sinus Figure 8. Bio-Oss (an organic bovine xenograft) being placed in anterior compartment with a syringe Figure 9. Bio-Oss (a xenograft) has been placed to a height of 15 mm Figure 10. Bio-Gide resorbable collagen membrane in place over the graft of the sinus. An antrostomy, or window, is made in the lateral wall with a diamond bur using either a surgical or a high speed hand piece. The bony window can then be rotated horizontally along with sinus membrane elevation or it can be completely removed. The Schneiderian (sinus) membrane is reflected across the sinus floor and then superiorly up the medial sinus wall. The elevated membrane thus becomes the superior and distal walls of a compartment in the lower 1/3 of the sinus that will receive the bone graft. Once the graft material is placed, the lateral window should be covered with a biologic barrier membrane prior to suturing the flap back into position. The graft is allowed to mature, with the formation of new bone around the graft particles, prior to implant placement (delayed approach) or the implants may be placed simultaneously with grafting if sufficient crestal bone is present to stabilize them. The implants are given sufficient time to integrate in the grafted sinus and then restored with traditional implant prosthetic components. The surgical procedure is demonstrated in Figures The goals of the sinus elevation procedure are the creation of vital bone in the posterior maxilla, the osseointegration of the implants placed in that bone and the survival of those implants under occlusal load. How successful we are in this endeavor will be affected by the decisions we make about graft material selection, membrane placement and implant surface selection. Within the last year, two evidence-based reviews have been published on the sinus elevation technique (Wallace & Froum, Del Fabbro et al). 6,7 Evidence-based reviews are structured, unbiased compilations of the best evidence available. The data from similar studies is then combined to enlarge the database in order to achieve greater statistical power. This combined data is then subjected to meta-analysis so that the variables that affect the outcome of this procedure can be isolated and their effects quantified. Evidence-Based Decision Making Graft Materials increase in implant survival from the average sinus lift survival rate of 91.8% to a survival rate of 98.6%. This is an implant survival rate that is as good as one can expect with implant placement in the anterior mandible. Surgical technique The lateral window technique begins with a full thickness mucoperiosteal flap to gain access to the lateral bony wall Autogenous bone Autogenous bone was the first graft material to be widely utilized as a sinus grafting material. Many early studies involved the harvesting of a block graft from the iliac crest and then stabilizing this graft with implants placed through the remaining crestal bone and into the graft. Autogenous bone grafts from the hip, knee and various intraoral sites have also been utilized in particulate form. The utilization of grafts of 100% autogenous bone has a number of disadvantages. Harvesting of this bone generally involves hospitalization (extraoral) or requires a second surgical site (intraoral), thus increasing the length of time of the surgery, the surgical risk 3

4 and the morbidity of the procedure. Clinicians have also reported a more-than-average graft resorption when using iliac bone. 8 A computerized tomographic study by Uchida, utilizing Sim/Plant diagnostic software, calculated that 5.47 cc of graft material would be required to graft a sinus for the placement of multiple 15 mm implants. 9 The 11 cc of graft material required for a bilateral case would generally exceed that which could be harvested intraorally. For the above-mentioned reasons it has become practical to utilize bone replacement grafts alone, or in combination with autogenous bone, as sinus grafting material. Demineralized freeze-dried bone Demineralized freeze-dried bone (DFDBA) has also been utilized as a sinus graft material. While used successfully by some clinicians, the results published following the Academy of Osseointegration Sinus Consensus Conference showed both poor bone quality and a poor implant survival rate (85%). Furthermore, this demineralized graft is susceptible to slumping, or settling, with a concomitant loss of graft height. It has a volumetric resorption rate second only to that of autogenous bone. 8 Xenografts Xenografts have been very well documented as a sinus grafting material. They have been used alone or as part of a composite graft combined with autogenous bone, venous blood or platelet-rich plasma. In the Wallace review, the survival rate for implants placed in xenografts was similar to that of implants placed in particulate autogenous bone grafts. 6 The Del Fabbro review was even more specific in the documentation of the utilization of xenografts. Survival rates for implants placed in 100% xenograft, composite grafts, and 100% autogenous bone grafts were 96%, 94.9% and 87.7% respectively as seen in Table 1. Table 1. Implant Survival Rates with Various Grafting Materials Type of graft # placed # failed survival rate % 100% Autogenous 3, % Composite graft 2, % 100% Bone replacement 1, % Studies by Hallman, Hising and Valentini all have shown a higher implant survival rate when using 100% Bio-Oss as a bone replacement graft compared to using either 100% autogenous bone or composite grafts of Bio- Oss and autogenous bone Efficacy of Xenografts The efficacy of xenografts is likely due to a combination of factors: 1. Osteoconductivity 2. Slow resorbability 3. The residual graft material does not interfere with osseointegration The most important factor that can be attributed to xenografts is their osteoconductivity. Osteoconductivity may be defined as the direct apposition of vital bone on the xenograft surface. This is very well demonstrated in Figure 11. This newly formed vital bone (red) is ultimately responsible for the osseointegration of the implant in the grafted site. Figure 11. Osteoconduction. Bone deposition directly on the Bio- Oss graft particles at 6 months. Stevenel s blue and picric acid fuchsin (Bio-Oss yellow, osteoid green, new bone red) Original magnification 20. A second feature of the xenograft material is that it is slowly resorbable when placed in the maxillary sinus. This quality both prevents slumping (loss of graft height) and adds approximately 25% to the overall mineral content of the matured graft. An average taken from 8 published histological studies showed 25% vital bone formation, 25% residual xenograft and 50% marrow in the matured sinus graft. The resulting 50% total mineralized tissue (new bone + residual graft) makes the future implant receptor site equivalent in density to that of type 2 (dense) bone. The third feature is the repeated histological finding that implants placed in sinuses grafted with Bio-Oss are never seen in direct contact with the graft material. This is evidence that the residual graft material, while providing support and density, does not interfere with osseointegration. Issues of safety are of paramount concern to us as dentists when placing graft material in the human body. A great amount of undue concern has been placed on xenogenic material due to the outbreak of bovine spongiform encephalopathy (BSE) in Europe. Regulations and testing of xenografts are quite extensive. The raw material for U.S. products is sourced from the long bones of U.S. cattle only. The material is processed by heat and chemicals to ensure that it is sterile and prion-free. For Bio-Oss the proof of deorganification is obtained through BioRad assay, SDS-PAGE testing and SDS-PAGE + Western blotting. To date, there has never been a reported case of disease transmission attributed to particulate xenografts. 4

5 Membranes Membrane placement is the second major variable evaluated in the sinus reviews. The Wallace review has shown that the utilization of a barrier membrane over the lateral window has a positive affect on implant survival. 6 The three controlled trials listed in Table 2 all showed higher implant survival rates when a membrane was used Further, twenty additional studies showed implant survival with a membrane to be 93.6% compared to 88.7% without a membrane. Table 2. Membrane vs. No Membrane (intra-study comparison in controlled trials) Study With membrane Without membrane Tarnow et al. Tawil et al. Froum et al. 28 Implants 100% 29 Implants 93.1% 133 Implants 99.2% 27 Implants 92.6% 32 Implants 78.1% 82 Implants 96.3% The advent of guided bone regeneration techniques in the early 1990 s improved our ability to repair compromised implant receptor sites. Sinus grafting may be considered as a form of guided bone regeneration within a cavity. Guided bone regeneration utilizes membranes to isolate the area of regeneration and exclude non-osteogenic connective tissue from the graft site. When a membrane is placed over a grafted bone defect, completely sealing the defect from the outside environment, the following characteristics are observed in the regenerated tissue beneath the membrane: 1. Corticalization of the graft surface 2. Contiguity of the graft particles 3. Increased vascularity of the maturing graft Figure 12. Clinical appearance of lateral window area 8 months after sinus grafting. Lateral wall is completely restored. Histological studies of sinus grafts by Tarnow et al. and Froum et al. both show these changes as well as a dramatic increase in vital bone content when a membrane is utilized compared to cases where it is not used (25% and 11.8% respectively in the Tarnow study). 17,19 Figure 12 shows a completely regenerated lateral window area eight months after sinus grafting with Bio-Oss and placing a Bio-Gide membrane over the window. As in guided bone regeneration, the first membranes widely utilized in sinus grafting were non-resorbable e-ptfe (Gore-Tex ) membranes. To be effective, these membranes had to be fixated by tacking them to the bone surface. Removal of the membrane required the flap reflection at the time of implant placement surgery to be as extensive as it was for the lateral window surgery. If bioabsorbable barrier membranes could be utilized over the lateral window, and achieve the same results, this latter surgery could be less extensive and therefore less traumatic. A recent study has compared the results utilizing either absorbable (Bio-Gide ) or non-absorbable barrier membranes (e-ptfe, Gore-Tex ) over the lateral window. The results show both a similar vital bone formation (17.6% and 16.9% respectively) and a similar implant survival rate (97.6% and 97.8% respectively) for the two types of membranes. 20 Implants A third variable that affects implant survival in sinus grafts is the surface texture of the implants that are placed in the graft. Both the Wallace (Table 3) and Del Fabbro (Table 4) reviews show a dramatic difference in implant survival when comparing rough to machined implants. 6,7 Table 3. Survival Rates for Rough vs. Machined Implants Surface Std error Mean Least sq. mean Machined Rough Table 4. Distribution of Implants and Overall Survival Rate According to Implant Surface Texture. Subgroup # Studies # Patients # Implants % Tot. of implants Implant failures Survival rate % Turned , % % Rough , % % Not classified , % 67 Total 2,053 6, % 588 The large differences observed in implant survival are most likely a result of the known differences in implant-bone contact achieved by the rough and smooth surfaces. Studies utilizing special implants that have both surfaces on the same implant show a large difference in implant-bone contact between the surfaces. By having both surfaces on the same implant, these studies rule out the variable of comparing implants that were placed in different sites. The study by Lazzara showed bone implant contact for Osseotite and machined surfaces to be 79.7% and 46.5% respectively in good quality bone but only 51.7% and 8.1% respectively in poor quality bone. 21 Trisi, in a similar study, has shown that the bone-implant contact with machined implants is usually less than you would expect given the 5

6 bone quality of the receptor site. 22 On the contrary, the Osseotite surface always had better than expected bone contact. Davies has shown that the textured Osseotite surface is better able to stabilize the blood clot on the surface, allowing for bone formation directly on the surface (contact osteogenesis). 23 The inability of the machined surface to stabilize the blood clot leads to retraction of the clot and bone formation away from the implant surface (distance osteogenesis). A recent study at the New York University Department of Implant Dentistry has shown that machine-surfaced implants are much more likely to fail than implants with textured surfaces when placed in sinus grafted cases with reduced residual crestal bone height. 24 This is yet another clinical deficiency resulting from the poor bone-implant contact that is established with a machined surface. Conclusions One result of the Wallace evidence-based review was the publication of the following statement by the American Academy of Periodontology: 6 There is evidence to indicate that the lateral window technique for the sinus bone augmentation procedure is successful at regenerating sufficient bone for implant placement. The implant survival rate is greater than 90% which is similar to implants placed in native bone. The evidence-based reviews further identified some of the important variables that affect the outcome of this procedure. They are: 1. Particulate bone grafts result in a higher survival rate than block grafts 2. Bone replacement grafts result in a higher implant survival rate than autogenous bone or composite grafts 3. Rough surface implants result in a higher survival rate than machine-surfaced implants 4. Membrane placement over the lateral window results in a higher implant survival rate than if a membrane is not used. Additional studies were presented in the present paper showing that the xenograft Bio-Oss achieves its predictable success through a combination of its osteoconductivity, its characteristic slow resorbability and its lack of interference with the process of osseointegration. Evidence was also presented to show that, with regard to bone formation and implant survival, comparable positive affects are achieved with the bioabsorbable Bio-Gide and the non-absorbabe Gore-Tex e-ptfe barrier membranes. A clinician can utilize an evidence-based decision-making process to dramatically improve implant survival rates in the grafted maxillary sinus. In the Wallace evidence-based review the average implant survival for the lateral window procedure was 91.8%. By making the two decisions to utilize rough surfaced implants and particulate bone grafts the implant survival rate became 94.5%. By making a third decision to place a membrane over the lateral window, the implant survival rate increased to 98.6%. The ability to place implants in the compromised posterior maxilla with a very high predictability will allow us, as clinicians, to more predictably treat our patients with more favorable treatment plans. Certainly, patient function and comfort will be improved if we choose to place fixed restorations instead of removable dentures in our partially and completely edentulous patients. References 1. Branemark 10 or 20 year data article 2. Boyne PJ, James RA. Grafting of the maxillary sinus floor with autogenous marrow and bone. J Oral Surg 1980;38: Summers RB. The osteotome technique: Part 3 Less invasive methods of elevating the sinus floor. Compend Contin Educ Dent 1994;15(6): Toffler M. Site development in the posterior maxilla using osteocompression and apical alveolar displacement. Compend Contin Educ Dent 2001;22: Bruschi GB, Scipioni A, Calesini G, Bruschi E. Localized management of the sinus floor with simultaneous implant placement: A clinical report. Int J Oral Maxillofac Implants 1998;13: Wallace SS, Froum SJ. Effect of maxillary sinus augmentation on the survival of endosseous dental implants. A systematic review. Ann Periodontol 2003;8: Del Fabbro M, Testori T, Francetti L, Weinstein R. Systematic review of survival rates for implants placed in the grafted maxillary sinus. Int J Periodontics Restorative Dent 2004;24: Jensen OT, Shulman LB, Block MS, Iacono VJ. Report of the sinus consensus of J Oral Maxillofac Implants 1998;13(supplement). 9. Uchida Y, Goto M, Katsuki T, Soejima Y. Measurement of maxillary sinus volume using computerized tomographic images. Int J Oral Maxillofac Implants 1998;13: Hallman M, Sennerby L, Lundgren S. A clinical and histologic evaluation of implant integration in the posterior maxilla after sinus floor augmentation with autogenous bone, bovine hydroxyapatite, or a 20:80 mixture. Int J Oral Maxillofac Implants 2002;17: Hising P, Bolin A, Branting C. Reconstruction of severely resorbed alveolar crests with dental implants using a bovine mineral for augmentation. Int J Oral Maxillofac Implants 2001;16: Valentini P, Abensur D. Maxillary sinus floor elevation for implant placement with demineralized freeze-dried bone and bovine bone (Bio-Oss): A clinical study of 20 patients. Int J Periodont Rest Dent 1997;17: Scarano A, Pecora G, Piatelli M, Piatelli A. Osseointegration in a sinus augmented with bovine porous bone mineral: Histological results in an implant retrieved 4 years after case insertion. A case report. J Periodontol 2004;75: Valentini P, Abensur D, Densari D, Graziani JN, Hämmerle CHF. Histological evaluation of Bio-Oss in a 2-stage sinus floor elevation and implantation procedure. A human case report. Clin Oral Implants Res 1998;9: Benke D, Olah A, Möhler. Protein-chemical analysis of Bio-Oss bone substitute and evidence on its carbonate content. Biomaterials 2001;22: Wenz B, Oesch B, Horst M. Analysis of the risk of transmitting bovine spongiform encephalopathy through bone grafts derived from bovine bone. Biomaterials 2001;22: Tarnow DP, Wallace SS, Froum SJ. Histologic and clinical comparison of bilateral sinus floor elevations with and without barrier membrane placement in 12 patients: Part 3 of an 6

7 ongoing prospective study. Int J Periodontics Restorative Dent 2000;20: Tawil G, Mawla M. Sinus floor elevation using a bovine bone mineral (Bio-Oss) with or without the concomitant use of a bilayered collagen barrier (Bio-Gide): A clinical report of immediate and delayed implant placement. Int J Oral Maxillofac Implants 2001;16: Froum SJ, Tarnow DP, Wallace SS, Rohrer MD, Cho S-C. Sinus floor elevation using anorganic bovine bone matrix (OsteoGraf/N) with and without Autogenous bone: A clinical, histologic, radiographic, and histomorphometric analysis Part 2 of an ongoing prospective study. Int J Periodont Rest Dent 1998;18: Wallace SS, Froum SJ, Tarnow DP, Cho S-C. Sinus augmentation using anorganic bovine bone (Bio-Oss ) with bioabsorbable and non-absorbable membranes. Int J Periodontics Restorative Dent 2005;25: accepted for publication. 21. Lazzara RJ, Testori T, Trisi P, Porter S, Weinstein RL. A human histologic analysis of Osseotite and machined surfaces using implants with 2 opposing surfaces. Int J Periodontics Restorative Dent 1999;19: Trisi P, Lazzara RJ, Rao W, Rebaudi A. Bone implant contact and bone quality: Evaluation of expected and actual bone contact on machined and Osseotite implants. Int J Periodontics Restorative Dent 2003;23: Dziedzic DM, Davies JE, et al. Proceedings of the 5th Biomaterials conference.university of Toronto Press 1996: Wallace SS, Elian N, Kim MG, Kim BS, Zaky J, Cho SC, Froum SJ, Tarnow DP. The relationship between residual crestal bone height and the implant survival rate in the augmented maxillary sinus. Submitted for publication Jan Registered Trademarks Bio-Oss and Bio-Gide are registered trademarks of Ed. Geistlich Söehne Ag Fuer Chemiche Industrie, licensed by Osteohealth Company. Osseotite is a registered trademark of Implant Innovations, Inc. Gore-Tex is a registered trademark of W.L. Gore & Associates, Inc. Author Profile Stephen S. Wallace, DDS Dr. Wallace is an Associate Professor at the New York University Department of Implant Dentistry. He is a Diplomat of the International College of Oral Implantologists and a Fellow of the Academy of Osseointegration. He maintains a private practice in periodontics in Waterbury, CT. Dr Wallace is a national and international speaker on topics relating to implant dentistry. He has published numerous articles on sinus elevation surgery and the effects of biologic width around implants. He is an editor of a maxillary sinus surgery text (Italian) and has authored chapters in sinus texts in the USA. Dr. Wallace has recently published an evidencebased review on sinus elevation surgery. Disclaimer This course has been made possible through an unrestricted educational grant by Osteohealth. Dr. Wallace has been paid an honorarium by Osteohealth to author this course. Reader Feedback We encourage your comments on this or any PennWell course. For your convenience, an online feedback form is available at 7

8 1. Inadequate crestal bone height for implant placement may result from a. periodontal bone loss b. pueumatization of the sinus c. both of the above d. none of the above 2. Sinus elevation surgery has been used for how many years? a. 1 b. 5 c. 15 d Variations in sinus elevation surgery include: a. lateral window antrostomy b. osteotome sinus elevation c. crestal core elevation 4. Implant survival in the grafted maxillary sinus is: a. generally poor b. generally favorable c. as high as implant placement in non-grafted bone d. much lower than that seen in non-grafted bone 5. Surgical technique for the lateral window procedure a. utilizes flapless surgery b. involves split thickness flap techniques c. involves full thickness flap entry d. involves bone surgery only 6. Exposing the sinus membrane is accomplished a. with bone chisels b. with osteotomes c. with burs d. with all of the above 7. Once outlined, the bony window in the lateral wall a. is hinged superiorly b. is removed c. both a and b above d. neither a or b above 8. The goals of sinus elevation are a. the creation of bone in the maxillary sinus b. integration of implants in the grafted sinus c. having the placed implants function under load 9. The best information that we have for achieving predictable results with the sinus elevation procedure are a. expert opinions b. evidence-based reviews c. commercial advertising brochures d. hands-on courses 10. Evidence-based reviews are good sources of information because they a. are unbiased b. consider the best available evidence c. gain statistical power by combining like data 11. Three important variables discussed in the evidence-based reviews are a. type of graft material, use of a membrane, sterile surgical technique b. method of flap entry, handling of the bone window, use of membrane c. type of graft material, use of a membrane, type of implant surface d. handling of the bone window, sterile surgical technique, use of membrane Questions 12. The first graft material to be utilized extensively in sinus grafting was a. autogenous bone b. demineralized freeze-dried bone c. composite grafts d. xenografts 13. Disadvantages when using autogenous bone may include a. need for hospitalization b. need for a second surgical site c. re-pneumatization of the sinus following grafting 14. Harvesting autogenous bone a. increases surgical time b. increases morbidity c. increases surgical risk 15. Demineralized freeze-dried bone as a graft material a. cannot be utilized successfully due to lack of mineral b. maintains its volume after grafting c. appears to have a lower success rate than other graft materials d. must be used as a composite graft 16. Xenografts for sinus grafting have been used a. alone b. mixed with blood c. as composite grafts with autogenous bone 17. Xenografts like Bio-Oss are successful because they a. are osteoconductive b. are slowly resorbable c. do not interfere with osseointegration 18. The most important factor in the success of Bio-Oss as a graft material is its a. slow resorbability b. osteoconduction c. non-interference with osseointegration d. ready availability 19. Bio-Oss bone replacement graft material a. is provided sterile b. is prion-free c. has a 100% safety record as a graft material 20. A bone replacement graft may be considered osteoconductive if a. vital bone forms directly on its surface b. it is slowly resorbed c. it has a high mineral content d. it is safe and readily available 21. Studies on implant survival with various grafting materials show highest implant survival rates when which of the following is utilized a. 100% autogenous bone b. composite grafts that include autogenous bone c. 100% bone replacement grafts 22. One of the following results is not seen when a membrane is placed over the lateral window a. corticalization of the graft surface b. fixation of the graft to the membrane surface c. contiguity of the graft particles d. increased vascularity of the maturing graft 23. When compared to bioabsorbable barrier membranes, non-absorbable (e-ptfe) barrier membranes placed over the window a. give better results b. are easier to place c. are easier to remove d. none of the above 24. In a study comparing the bioabsorbable Bio-Gide membrane to the nonabsorbable e-ptfe membrane, use of the Bio-Gide membrane resulted in a. the same bone quality b. the same implant survival rate c. less invasive implant placement surgery 25. Use of a membrane over the lateral window results in the following a. increase in vital bone percentage in the matured graft b. increase in implant survival on implants placed in the grafted sinus c. both a and b above d. neither a or b above 26. With regard to implant surface micromorphology, both the Wallace and Del Fabbro reviews have shown a. higher implant survival with textured than machined surfaces b. higher implant survival with machined than textured surfaces c. similar implant survival with both surfaces d. no comparisons could be made due to insufficient data 27. The difference in implant survival between the rough and machined surfaced implants were said be due to which of the following a. better primary stability with the rough surface b. better clot retention on the rough surfaced implants c. better implant to bone interface on the rough surfaced implants d. b and c above 28. The better implant to bone interface on the rough surface is due to a. greater primary stability achieved with the rough surfaced implants b. contact osteogenesis c. distance osteogenesis d. the use of implants with 2 surfaces 29. According to a recent NYU study, the increased failure rates when implants are placed into minimal crestal bone may be due to a. a general lack of primary stability b. the micro-motion resulting from inadequate primary stability c. the poor implant to bone contact achieved with the machined surface 30. The high implant survival rates that can be achieved with maxillary sinus grafting allow clinicians to a. predictably treat patients with a compromised posterior maxilla b. utilize fixed as opposed to removable appliances c. successfully place implants in the compromised posterior maxilla 8

9 ANSWER SHEET Maxillary Sinus Augmentation Name: Title: Specialty: Address: City: State: ZIP: Telephone: Home ( ) Office ( ) Requirements for successful completion of the course and to obtain dental continuing education credits: 1) Read the entire course. 2) Complete all information above. 3) Complete answer sheets in either pen or pencil. 4) Mark only one answer for each question. 5) A score of 70% on this test will earn you 4 CE credits. 6) Complete the Course Evaluation below. 7) Make check payable to PennWell Corp. Educational Objectives 1. Identify appropriate graft materials for sinus surgery. 2. Compare implant survival rates pertaining to membrane placement. 3. Select implants based on surface texture. Course Evaluation Please evaluate this course by responding to the following statements, using a scale of Excellent = 5 to Poor = Were the individual course objectives met? Objective #1: Yes No Objective #3: Yes No Objective #2: Yes No 2. To what extent were the course objectives accomplished overall? Please rate your personal mastery of the course objectives Mail completed answer sheet to Academy of Dental Therapeutics and Stomatology, A Division of PennWell Corp. P.O. Box 116, Chesterland, OH or fax to: (440) For immediate results, go to and click on the button Take Tests Online. Answer sheets can be faxed with credit card payment to (440) , (216) , or (216) Payment of $59.00 is enclosed. (Checks and credit cards are accepted.) If paying by credit card, please complete the following: MC Visa AmEx Discover Acct. Number: Exp. Date: Charges on your statement will show up as PennWell 4. How would you rate the objectives and educational methods? How do you rate the author s grasp of the topic? Please rate the instructor s effectiveness Was the overall administration of the course effective? Do you feel that the references were adequate? Yes No 9. Would you participate in a similar program on a different topic? Yes No 10. If any of the continuing education questions were unclear or ambiguous, please list them. 11. Was there any subject matter you found confusing? Please describe. 12. What additional continuing dental education topics would you like to see? AGD Code 691 PLEASE PHOTOCOPY ANSWER SHEET FOR ADDITIONAL PARTICIPANTS. AUTHOR DISCLAIMER The author of this course has been paid an honorarium by Osteohealth to author this course. SPONSOR/PROVIDER This course was made possible through an unrestricted educational grant from Osteohealth. No manufacturer or third party has had any input into the development of course content. All content has been derived from references listed, and or the opinions of clinicians. Please direct all questions pertaining to PennWell or the administration of this course to Machele Galloway, 1421 S. Sheridan Rd., Tulsa, OK or macheleg@ pennwell.com. COURSE EVALUATION and PARTICIPANT FEEDBACK We encourage participant feedback pertaining to all courses. 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To find out if this course or any other PennWell course has been approved by DANB, please contact DANB s Recertification Department at FOR-DANB, ext RECORD KEEPING PennWell maintains records of your successful completion of any exam. Please contact our offices for a copy of your continuing education credits report. This report, which will list all credits earned to date, will be generated and mailed to you within five business days of receipt. CANCELLATION/REFUND POLICY Any participant who is not 100% satisfied with this course can request a full refund by contacting PennWell in writing by the Academy of Dental Therapeutics and Stomatology, a division of PennWell 9