Abstracts - Implant dentistry

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Implant Dentistry

01. Clinical and Radiographic Evaluation of Implant-Retained Mandibular Overdentures With Immediate Loading. 02. Histologic Comparison of Light Emitting Diode Phototherapy-Treated Hydroxyapatite-Grafted Extraction Sockets: 03. Peri-Implant Bone Regeneration With Calcium Sulfate: A Light and Transmission Electron Microscopy Case Report. 04. Comparative Analysis of 4 Impression Techniques for Implants. 05. Clinical and Histological Evaluation of Immediate-Loaded Posterior Implants in Nonhuman Primates. 06. Factors Influencing the Preservation of the Periimplant Marginal Bone. 07. Immediate Provisionalization on a New Implant Design for Esthetic Restoration and Preserving Crestal Bone. 08. Implants in Conjunction With Removable Partial Dentures: A Literature Review. 09. A New Atraumatic System for Tooth Removal and Immediate Implant Restoration. 10. Lingual Vascular Canals of the Mandible: The Risk of Bleeding Complications During Implant Procedures. 11. Computer-Aided Design/Computer-Aided Manufacturing Surgical Guidance for Placement of Dental Implants: Case Report. 12. Bifid Mandibular Canal in Japanese. 13. Medical Contraindications to Implant Therapy: Part II: Relative Contraindications. 14. Multitier Technique for Bone Augmentation Using Intraoral Autogenous Bone Blocks. 15. Mineralized Bone Allograft-Plug Socket Augmentation: Rationale and Technique. 16. A Histomorphogenic Analysis of Bone Grafts Augmented With Adult Stem Cells. 17. Aesthetics in Oral Implantology: Biological, Clinical, Surgical, and Prosthetic Aspects. 18. The Integration of Chitosan-Coated Titanium in Bone: An In Vivo Study in Rabbits. 19. Effect of Tumor Necrosis Factor-[alpha] Gene Polymorphism on Peri-Implant Bone Loss Following Prosthetic Reconstruction. 20. Antibacterial Effect of Zinc Phosphate Mineralized Guided Bone Regeneration Membranes. 21. Genotoxicity of Corrosion Eluates Obtained From Endosseous Implants. 22. Knowledge, Attitude, and Practice of Dental Implantology in Nigeria. 23. An Update on Implant Placement and Provisionalization in Extraction, Edentulous,and Sinus-Grafted Sites 23. Cement Selection for Cement-Retained Crown Technique with Dental Implants

Cement Selection for Cement-Retained Crown Technique with Dental Implants Encolosed is an abstract from an article a couple of years ago ranking different kinds of cements. In my opinion, there is not one cement which you can say is for every situation. There are so many variables involved...nuber of abutments, length of abutments, etc. I have also spoken to many clinicians who are also going back to zinc phosphate cement...don't laugh!! The feeling is that if any cement is left below the tissue, since it is water soluble it will wash away - Barry Journal of Prosthodontics Volume 17 Issue 2, Pages 92 - 96 Cement Selection for Cement-Retained Crown Technique with Dental Implants James L. Sheets, DDS 1 , Charles Wilcox, DDS, MS 1 , & Terry Wilwerding, DDS, MS 2 1 Professor, Department of Prosthodontics, Creighton University School of Dentistry, Omaha, NE 2 Professor correspondence James L. Sheets, Department of Prosthodontics, Creighton University School of Dentistry, 2500 California Plaza, Omaha, NE 68178. E-mail: jsheets@creighton.edu Copyright 2007 by The American College of Prosthodontists KEYWORDS Implant , cement , cement-retained crown ABSTRACT Purpose: The purpose of this study was to assess and compare the retentive nature of common dental cements that have been adapted for use in the implant abutment cement-retained crown (CRC) technique with those specifically formulated for this purpose. Materials and Methods: Ten regular diameter implant analogs were embedded in stainless steel disks. Unmodified CRC abutments were attached and torqued to 30 Ncm. Test crowns were waxed and cast with base metal alloy. Castings were fitted, cleaned with aluminum oxide, and steam cleaned prior to application of the cement. The cements used were: (1) Temp Bond, (2) UltraTemp, regular, (3) UltraTemp firm, (4) ImProv with petroleum jelly coating of crown, (5) ImProv without petroleum jelly, (6) Premier Implant with KY Jelly coating of abutment, (7) Premier Implant without KY jelly, (8) TR-2, (9) Fleck's, (10) Ketac Cem Aplicap, and (11) Fuji Plus Capsule. After cementation, assemblies were stored for 24 hours. Each sample was subjected to a pull-out test using an Instron universal testing machine at a crosshead speed of 5.0 mm/min. Loads required to remove the crowns were recorded, and mean values for each group determined. A one-way ANOVA and a post hoc least square difference (LSD) test were done for pairwise comparison at a confidence interval of 95%. Results: The mean values (±SD) of loads at failure (n = 10) for various cements were as follows (N): Ultratemp, regular 358.6 (±38.2) (Group A), ImProv without petroleum jelly 172.4 (±59.6) (Group B), Fleck's 171.8 (±62.2) (Group B), Ketac Cem 167.8 (±69.1) (Group B), UltraTemp firm 158.8 (±62.7) (Group BC), Fuji Plus 147.5 (±69.7) (Group BC), Premier without KY jelly 131.6 (±31.8) (Group BC), ImProv using petroleum jelly 130.8 (±42.5) (Group BC), Temp Bond 117.8 (±48.3) (Group C), TR-2 41.2 (±16.6) (Group D), and Premier with KY jelly 31.6 (±24.8) (Group D). Groups with the same letter were not significantly different. Conclusions: Within the limitations of this in vitro study, it is not suggested that any one cement is better than another at retaining cement-retained crowns (CRCs) to implant abutments or that a threshold value must be accomplished to ensure retention. The ranking of cements presented is meant to be a discretionary guide for the clinician in deciding the amount of desired retention between castings and implant abutments. -------------------------------------------------------------------------------- An Update on Implant Placement and Provisionalization in Extraction, Edentulous,and Sinus-Grafted Sites Paul S. Petrungaro, DDS, MS Abstract Provisionalization of dental implants at placement has become more prominent in the field of implantology over the past several years, especially in the esthetic zone. The benefits of this treatment option include immediate tooth replacement, formation and maintenance of esthetic soft-tissue contours, containment for bone-grafting and tissue-regenerative procedures, and an improved sense of the patient's perception of the implant process. The blending together of the surgical and prosthetic/esthetic phase has never been more important as implant systems, abutment options, and surgical techniques have helped optimize procedures that can be accomplished at the surgical visit. This article reviews the guidelines for surgical success first described by the author in 2003 and expands upon those results. This article highlights the results of more than 3,200 immediately restored implants placed in edentulous, fresh extraction sockets, and sinus-grafted sites, over an 8-year period, and presents a case for each area of placement. Incorporating dental implants into the treatment-planning process for replacement of missing teeth has become commonplace in the contemporary surgical and restorative practice because of their high success rates.1-3 The conventional multistage approach to implant reconstruction has accounted for the bulk of implant protocols that have amassed these success rates.1-3 While these procedures are predictable and reliable, because of the multiple surgical procedures they often require, esthetics can be compromised. Additionally, these treatment plans require additional time because each procedure requires time to heal. Further, these protocols often require a removable provisional prosthesis or no provisional is provided. Advancements in surgical protocols have allowed implant surgeons to provide the restoring dentist and patient with a fixed, nonloaded restoration during surgery.4Wöhrle ,4 Salama and colleagues,5 Saadoun and LeGall,6 and Petrungaro7 have presented guidelines for surgical protocols that allow the implant team to place predictable and esthetic provisionals during surgery. Placing a fixed provisional at implant placement has been shown to contribute to the early foundation for esthetic final implant-supported restorations by aiding in the creation of esthetic soft-tissue contours and emergence profiles.8 Several Author's have documented the importance of the dento-gingiva-implant complex,9 describing how parameters for success with restorations on natural teeth, regarding the foundation for soft-tissue emergence profiles along with a healthy, mature biologic width,10 can be extrapolated to implant-supported restorations placed within the natural tooth space (single-tooth replacement) or implant-implant space11 (multiple adjacent implant sites). Before the inception of surgical procedures, clinicians must incorporate, with esthetic considerations, the dimension for the final prosthetic restoration.12 Use of a surgical stent designed to allow the surgeon to translate the dimensions of the final restoration to the surgical field have been shown clinically to be effective in fostering this type of communication within the implant team.13 Kan and Rungcharassaeng,14 and Saadoun,15 have presented and established surgical rationales for immediate placement and provisionalization of anterior single-tooth implants. Petrungaro has presented a surgical protocol for posterior implants in the sinus-grafted region as well.8,16 This article will review a surgical protocol for the immediate placement and provisionalization of dental implants in single and multiple sites. (The surgical protocol was first described in Petrungaro PS. Immediate implant placement and provisionalization in edentulous, extraction, and sinus grafted sites. Compend Contin Educ Dent. 2003:24(2):95-113.) The guidelines presented are applicable to edentulous, extraction, and sinus-grafted sites. Table 1 and Table 2 report the success rates for more than 3,200 implants placed over an 8-year period. Three cases will demonstrate the presented protocol. Guidelines for Determining When to Perform Immediate Implant Placement and Restoration Procedures Pretreatment Planning The implant team should conduct a complete medical and dental evaluation before performing any surgical protocols. Maxillary and mandibular study models should be obtained and mounted on an articulator. Evaluation of the surgical site involves a prescription to the dental laboratory for a diagnostic wax-up of the hard and soft tissues that need to be replaced. After evaluating the diagnostic wax-up, the laboratory technician converts it to a surgical guide/temporary restoration. The TempStent II method,17 which the author developed, allows the restorative dentist to communicate to the surgeon the parameters necessary for a successful and biologically sound implant-supported res-toration. It also enables the surgeon to predetermine the angulation and spatial position of the implant, as well as to visualize the position of the implant collar and its relationship to the sulcular portion of the planned restoration and interimplant bone contours. Additionally, stock titanium or zirconia abutments can be prepared and the temporary approximated before the initial surgical visit. Radiologic analysis should consist of periapical and/or a panoramic radiograph at the site(s) to be treated. Additionally, the incorporation of cone-beam imaging techniques can increase greatly the implant team's knowledge of the type of ridge contours that exist before treatment. Imaging software can allow the implant team to plan appropriate sizes and dimensions of implant fixtures, determine where grafting will be required, and fabricate surgical guides that can simplify the implant surgical process. Surgical Technique Preoperative antibiotic administration, Table 3 Atraumatic tooth removal, sinus elevation, or edentulous site preparation with care given to preserve the facial cortical plate in extraction sockets Debridement of existing periodontal/periapical infection and/or periodontal ligament by mechanical and rotary instrumentation (eg, high-speed handpiece with a round No. 6 or 8 surgical diamond using copious water irrigation) Implant Selection and Placement First, the implant of choice for this technique should be one with a self-tapping thread design. Second, the implant should be tapered, which provides the best chance for obliteration of the coronal portion of the socket and mimics the root's natural convergence to the apical portion of the socket. Third, the implant surface should be roughened, with surface enhancements to promote a rapid integration and enhance the initial stabilization of the fixture. Last, as the procedure has continued to evolve, the author has observed that the polished implant collar should be no greater than 1 mm in height. This height allows the final position of the implant to have the polished collar in a position just superior to the crest of the bone. This collar position allows the soft tissue to attach in the region of the collar, while the enhanced, roughened implant surface at the first thread, or at its smooth transfer from the polished collar into the roughened surface, allows for bone attachment. The implant collar should be placed with the superior position of the polished collar equal to the line drawn from the facial height of contour (buccal bone height at the midfacial point) of the contralateral tooth to be replaced (ie, central/central, lateral/lateral, etc). Placing the implant in this fashion has been clinically observed to eliminate the "dieback" phenomenon and preserve the interdental bone and soft tissues. Grafting Material Autogenous bone is the best grafting material available. It is osteoconductive, osteoinductive, and osteogenic.18-21 However, a drawback of autogenous bone is the required second surgical site for harvesting the bone tissue. Many harvesting techniques require complicated surgical procurement and add significant surgical time and morbidity. Other options include the use of allogenic, alloplastic, and xenographic22,23 grafting materials, either with or without the use of various regenerative barriers. The use of these options has been well documented.24 If a nonautogenous grafting material is to be used, it should be biocompatible with the host tissue, osteoconductive, 25-29 osteoinductive,30,31 and osteotrophic.32,33 Not all allogenic or alloplastic grafting materials have these important qualities. Some must rely on a vehicle to reconstitute their granular form. The author34-36 and others37-39 have observed that platelet-rich plasma (PRP) can enhance the osteoconductiveâ€"and possibly the osteoinductiveâ€"properties of various allogenic, alloplastic, and xenographic materials. Platelet-Rich Plasma An ideal autogenous vehicle to reconstitute an alloplastic or allogenic substrate is PRP.37,39 PRP (autologous platelet gel) is developed from autologous blood with a cell separator. The cell separator used in the author's cases has a dual-spin cycle that completes the separation in 12 minutes (SmartPreP®, Harvest Technologies Corp, Plymouth, MA). Centrification of 55 mL of whole blood results in 10 mL of PRP that, when simultaneously mixed with thrombin and calcium chloride, results in the degranulation of the platelets and subsequent release of growth factors, which stimulate both hard- and soft-tissue maturation and promote healing. For this reason, PRP is an ideal vehicle to reconstitute the substrate because it enhances the oteoconductive qualities, and perhaps osteoinductive properties, of the allogenic, alloplastic, or xenographic graft materials. In addition, PRP has been observed to accelerate soft-tissue maturation, which allows the gingival tissues to heal rapidly with minimal postsurgical contour alterations. Table 4 lists the substances released by the degranulated platelets. However, controversy is present over the use of PRP in surgical dentistry. It is important to understand that not all PRP preparation systems are the same. PRP preparation systems range from simple centrifuges to sophisticated dual, one- to five-pin units with variable revolutions. Variations on percentages of platelet yield and coefficient of variability can alter greatly the effects of the platelets on healing. Abutment Selection An abutment should be selected by using the carrier mechanism of the implant system, a dedicated provisional abutment, a contoured stock abutment (which can be used as a final abutment), or a stock zirconia abutment. Before use, many of these abutments require preparation. Incorporating the temporary/surgical guide system used by the author allows for this preparation to be accomplished in advance in the dental laboratory. Advanced abutment preparation eliminates the repeated removal of carrier mechanisms, intraoral preparation of the abutment (which can produce heat and micromovement via vibration), and the insertion of impression copings for implant indexing at the time of placement. It is important to remember that many times, with immediate tooth removal/immediate implant placement (especially in sinus elevations), the quality of bone is compromised; whatever the surgeon can do to minimize external forces to the fixture will be beneficial. In cases where the stock abutment provided does not allow for an appropriate path of insertion for the restoration because of the angle of implant placement, a stock angled abutment that can be easily prepared will suffice. TEMPORARY MATERIAL AND CONSTRUCTION As mentioned previously, the temporary, along with the surgical guide, is constructed in the laboratory after evaluation of the diagnostic wax-up. The TempStent II method uses the TempStent II surgical guide, which can be retrofitted into an esthetic provisional restoration that closely mimics that of the planned final restoration in regard to emergence-profile formation, interdental contours, contact points, and gingival contour at the facial marginal aspect. Because TempStent II surgical guides are constructed to the exact parameters of the planned final restoration, the relationship to adjacent teeth and/or implants is brought to the surgical field, allowing for exact implant placement. After the implant has been placed, the surgical guide can be retrofitted onto the implant and the parameters for construction of the final restoration secured. Conventional surgical guides do not allow for this transfer or information, including contact-point relationships, emergence-profile formation, and parameters for the final esthetic restoration. On final placement of the temporary, the patient's occlusion must be evaluated carefully. The author recommends that the provisional have no occlusal contact in the centric relation position, in addition to no lateral excursive or protrusive contacts. At 3 months, or 4 to 5 months in sinus-grafted cases, the prosthodontist or reconstructive dentist can proceed with the fabrication of the final implant-supported restoration. After the final impression appointment, the temporary restoration can be recemented with temporary cement and, again, confirmation of nonload obtained. Suture Material When suturing is indicated, a 5.0 monofilament (Monocryl®, Ethicon, Inc, Somerville, NJ) or 4.0 Vicryl Rapide® (Ethicon, Inc) suture is recommended by the author. In cases where advanced stabilization of the wound is necessary, 5.0 monofilament suture material is indicated because it is nonabsorbable and aids in stabilization of the wound. Tissue-Sculpting Abutment At the 3-month postoperative appointment, the prosthodontist or reconstructive dentist should replace the initial provisional abutment/temporary complex with a tissue-sculpting abutment and provisional. In cases where the final abutment was seated at the initial surgical visit, a high-quality impression that registers the esthetic tissue contours will be required. In cases where a stock titanium, plastic provisional, or temporary abutment was placed and, where there was esthetic or prosthetic requirements, a custom or zirconia abutment will be required and a fixture level impression will be necessary. If necessary, an additional provisional restoration can be constructed and used for an extended period of time, especially in the esthetic zone, to create and form emergence profiles. Final Restoration Fabrication of the definitive prosthetic implant restoration (abutment/crown complex) and placement of the final restoration often is completed within 3 months (5 months in sinus-grafted cases). Contoured titanium or stock titanium abutments commonly are used as final abutments to support metal-based ceramic restorations. Depending on the esthetic requirements of the case, construction of an all-ceramic, gold with opaquing, or a contoured, preformed zirconia abutment can meet the esthetic needs of all-ceramic restorations. If the restoring dentist wishes to place a custom abutment, he or she should use a routine impression technique at fixture level with a transfer coping. After fabrication of the custom abutment, the abutment is seated and torqued at 30 Ncm. Then, the implant-supported restoration is completed as normal. Occlusal evaluation of the final restoration is imperative for long-term clinical success. A restoration that has the proper occlusal function in centric relation, and protrusive, right, and left lateral excursions, is necessary for the long-term clinical success of the implant complex.1-3 Postoperative Course As stated earlier, the prescribed healing phase is 3 months in immediate extraction or edentulous ridge cases, and 4 to 5 months in sinus-grafted cases. After the healing phase, if the restoring dentist plans to use the stock abutment seated at the initial visit, the abutment is torqued to 30 Ncm and the temporary is recemented. Routine restorative procedures are followed from that point. Final digital periapical radiographs of the treated sites are taken to register the interproximal alveolar bone contours. Additionally, a panoramic or cone-beam image should be obtained to evaluate the peri-implant area and 360° contour of the alveolar bone surrounding the implant fixture and restoration. The following case reports demonstrate the immediate implant placement and provisionalization procedure outlined in an edentulous site, an immediate extraction site, and a sinus-grafted site. Case 1 A 54-year-old, nonsmoking woman presented for treatment of an edentulous site that had been previously restored with a Maryland bridge (Figure 1 View Figure). The tooth originally had been removed without a ridge preservation procedure, which resulted in loss of the buccal-palatal dimension of the edentulous ridge. The Maryland bridge had recurrent bonding failure to the abutment teeth, and the restorative dentist had recommended implant placement at the right central incisor site, with subsequent esthetic enhancement of the adjacent dentition. The preoperative periapical radiograph (Figure 2 View Figure) showed adequate ridge height and an adequate intertooth space sufficient to create an esthetic emergence profile for the final implant-supported restoration. After administration of an appropriate local anesthetic, a TempStent II surgical guide was inserted over the surgical area. Using a 2-mm twist drill, the planned implant site was marked, followed by removal of the surgical guide. Then, using a football shaped diamond, the esthetic emergence profile was created, following the balance and symmetry of the gingival emergence of teeth Nos. 7 and 9 (the contoured emergence profile can be seen in Figure 3 View Figure). Using a Petrungaro Elevator (Salvin® Dental Specialties, Inc, Charlotte, NC), a full thickness flap was elevated creating a "pouch" at the facial of the edentulous site No. 8. This "pouch" allowed for the elevation of the buccal contour of the edentulous site and a confined space for the allogenic graft to be placed. After widening of the surgical site to the adequate dimension, a 3.7 mm x 13 mm Tapered Screw-Vent® implant (Zimmer Dental, Carlsbad, CA) was placed (Figure 3 View Figure). Then, the carrier mechanism was removed and a PRP-enhanced allogenic graft was placed. The graft complex, PRP and Puros® Allograft (Zimmer Dental) (1-mm to 2-mm sized cancellous particles) was reconstituted chairside several minutes before placement. The graft complex was placed by minimally invasive means into the "pouch" that was created earlier, and enough graft material inserted to slightly overbuild the facial contour of the right central incisor site (Figure 4 View Figure). Then, the cover screw was removed, a contour abutment, 341S-type (Zimmer Dental), was inserted over the implant (Figure 5 View Figure), and the screw was hand tightened. Following the manufacturer's instructions, the TempStent II surgical guide was retrofitted to create the final esthetic provisional restoration, which was cemented with strong temporary cement. The immediate postoperative digital periapical radiograph can be seen in Figure 6 View Figure). The provisional restoration was nonfunctional in protrusive and centric relation movements. After an uneventful 3-month healing phase, the patient was released to the restorative clinician for construction of the final implant restoration (Figure 7 View Figure and Figure 8 View Figure). Case 2 A 51-year-old, nonsmoking woman presented for treatment of fractured teeth at the Nos. 9 and 11 sites (Figure 9 View Figure). The teeth had a history of repeated root canal treatment, multiple bridge attempts and, with the most recent bridge failure, the teeth had become nonrestorable. The restoring dentist referred her for tooth removal and implant placement at sites Nos. 9 and 11, with ovoid pontic-site formation at tooth No. 10. The preoperative digital periapical radiograph can be seen in Figure 10 (View Figure). After creating maxillary and mandibular study models, taking a face-bow transfer, and mounting the casts on an articulator, the TempStent II surgical guide/provisionalization system was fabricated. After administration of an appropriate local anesthetic by infiltration, teeth Nos. 9 and 11 were carefully removed by an atraumatic extraction technique, taking great care not to traumatize the gingival tissues. After removing the teeth, the extraction sites were debrided by mechanical techniques (curetting with a molt curette) and rotary instrumentation (round No. 8 diamond) with copious irrigation to remove all remnants of the periodontal ligament space, any granulation tissue, and/or any remnants of residual tooth infection. Then, the TempStent II surgical guide was inserted and initial site coring accomplished in the extraction sockets (Figure 11 View Figure). After appropriate site development and preparation, two 3.7 mm x 13 mm Tapered Screw-Vent implants were placed by minimally invasive techniques (Figure 12 View Figure). Using the surgical guide, the edentulous site at No. 10 was marked for creation of an ovoid pontic site. After removal of the implant carriers, a PRP and Puros Allograft complex was placed and heavily condensed into the peri-implant defects to the level of the implant collar (Figure 13 View Figure). Additional deepening of pontic site also was accomplished at this time. After retrofitting of the TempStent II guide into the provisional, the contours and emergence profiles of the provisional restoration were corrected, including those of the ovoid pontic site. The restoration was cemented with strong temporary cement, and the occlusal parameters adjusted, making the provisional restoration nonfunctional in the centric relation, protrusive, and right and left lateral excursive movements. After a 3-month healing and observation phase, the restorative dentist constructed a 3-unit implant-supported restoration (Figure 14 View Figure). After case completion, a cone-beam radiographic image of the facial aspect of the implant at the central incisor site was taken (Figure 15 View Figure). Case 3 A 63-year-old, nonsmoking man presented for rehabilitation of his failing dentition (Figure 16 View Figure). After consultation with the restorative dentist and the patient, the decision was made to keep the patient in premolar occlusion (as he had been functioning for years), remove all failing and/or guarded/hopeless teeth immediately, and maintain his present vertical dimension. The restorative dentist prepared all teeth that were to remain, gathered maxillary and mandibular study models and a face-bow transfer, and had the laboratory technician fabricate a TempStent II surgical guide and provisional restoration that would be used at the initial surgical visit. Additionally, the laboratory technician prepared the planned implant sites on the study models and placed implant analogues into the prepared sites with acrylic material in the study models, which held the analogues in place. After the acrylic material set, plastic provisional abutments (HLPT series, Zimmer Dental) were selected to match the implants to be used, placed over the analogues, and prepared for draw (Figure 17 View Figure). Use of this technique simplified the delivery system of the provisional abutments and extensive provisional restoration. Using techniques described previously in this article, the hopeless teeth were removed, sites debrided, and implants placed into the planned sites. The TempStent II then was seated over the area, and the implant placement confirmed (Figure 18 View Figure). The peri-implant defects were corrected by the minimally invasive grafting technique described previously, using the PRP and Puros Dermis Allograft complex. After the peri-implant defects were corrected, the provisional abutments were removed from the study models and transferred to the implants, and the Temp-Stent II retrofitted following techniques described previously (Figure 19 View Figure). The patient underwent a 4-month healing and observation phase before the final restorative procedures. Ceramic custom abutments were placed on teeth Nos. 6 through 8, and final screw-retained implant-supported restorations were placed at site Nos. 5, 12, and 13 (Figure 20 View Figure). Note the balance and symmetry of the facial of teeth Nos. 6 through 8 to that of the teeth Nos. 9 through 11. At 1.5 years after surgery, the clinical appearance of the implant-supported restoration at the right central incisor site resembled the natural left central incisor (Figure 21 View Figure). The digital panoramic radiograph can be seen in Figure 22 (View Figure). Conclusion Dental implants have become a common and acceptable part of treatment plans for those patients requiring replacement of single or multiple teeth. The conventional method of implant treatment requires a multistep process, often times with multiple surgical procedures. In the past several years, new treatment options have been introduced, and the procedures have been documented clinically as highly successful. Immediate provisionalization of dental implants allows multiple procedures to be accomplished at the initial and sole surgical visit. Minimally invasive surgical procedures (bone grafting and implant place-ment) help clinicians to conserve gingival and alveolar tissues as well as papillary contours. Using a provisional abutment/crown complex allows clinicians to maintain the width of the root surface area at a constant dimension. This constancy allows the clinician to reconstruct the lost buccal plate, while the implant fixture is integrating. Patient benefits include shortened treatment times, reduced postoperative pain and swelling, and immediate use of an esthetic, nonremovable provisional. The author has observed an overall success rate of 98.9% over 8 years. Additional clinical studies are necessary to document and substantiate the long-term success of the immediate restoration procedure outlined in this article. Disclosure The author is a consultant for Zimmer Dental and a shareholder in Harvest Technologies Corporation. References 1. Adell R, Lekholm U, Rockler B, et al. A 15-year study of osseointegrated implants in the treatment of the edentulous jaw. Int J Oral Surg. 1981;10(6):387-416. 2. Adell R, Eriksson B, Lekholm U, et al. Long-term follow-up study of osseointegrated implants in the treatment of totally edentulous jaws. Int J Oral Maxillofac Implants. 1990; 5(4):347-359. 3. Babbush CA. Dental Implants: The Art and Science. 2nd ed. Philadelphia, PA: W.B. Saunders Co; 2001:201-216. 4. Würhle PS. Single-tooth replacement in the aesthetic zone with immediate provisionalization: fourteen consecutive case reports. Pract Periodontics Aesthet Dent. 1998;10(9):1107-1114. 5. Salama H, Salama MA, Garber D, et al. The interproximal height of bone: the guidepost to predictable aesthetic strategies and soft tissue contours in anterior tooth replacement. Pract Periodontics Aesthet Dent. 1998;10(9):1131-1141. 6. Saadoun AP, Le Gall MG. Periodontal implications in implant treatment planning for aesthetic results. Pract Periodontics Aesthet Dent. 1998;10(5):655-664. 7. Petrungaro PS. Immediate implant placement and provisionalization in edentulous, extraction, and sinus grafted sites. Compend Contin Educ Dent. 2003;24(2):95-113. 8. Petrungaro PS. Implant placement and provisionalization in extraction, edentulous, and sinus grafted sites: a clinical report on 1500 sites. Compend Contin Educ Dent. 2005; 26(12):879-890. 9. Kois JC. Altering gingival levels: the restorative connections. Part 1: biologic variables. J Esthet Restor Dent. 1994;6:3-7. 10. Tarnow DP, Magne AW, Fletcher P. The effect of the distance from the contact point to the crest of bone on the presence or absence of the interproximal dental papilla. J Periodontol. 1992;63(12):995-996. 11. Tarnow DP, Cho SC, Wallace SS. The effect of inter-implant distance on the height of the inter-implant bone crest. J Periodontol. 2000;71(4):546-549. 12. Salama H, Salama MA. The role of orthodontic extrusive remodeling in the enhancement of soft and hard tissue profiles prior to implant placement: a systematic approach to the management of extraction site defects. Int J Periodontics Restorative Dent. 1993;13(4):312-333. 13. Petrungaro PS, Maragos C, Matheson O. Using the Master Diagnostic Model to enhance restorative success in implant treatment. Compend Contin Educ Dent. 2000;21(1):33-46. 14. Kan JY, Rungcharassaeng K. Immediate placement and provisionalization of maxillary anterior single implants: a surgical and prosthetic rationale. Pract Periodontics Aesthet Dent. 2000;12(9):817-826. 15. Saadoun AP. Immediate implant placement and temporization in extraction and healing sites. Compend Contin Educ Dent. 2002;23(4): 309-326. 16. Petrungaro PS. Immediate restoration of dental implants in conjunction with maxillary sinus elevation procedures: an initial report of 77 implant sites. International Magazine of Oral Implantology. 2002;4(3):6-16. 17. Petrungaro PS. Using the TempStent technique to simplify surgical stent and esthetic temporary fabrication in immediately restored implants in the aesthetic zone. Contemporary Esthetics and Restorative Practice. 2002;6(5)84-90. 18. Jensen J, Sinder-Pedersen S. Autogenous mandibular bone grafts and osseointegrated implants for reconstruction of the severely atrophied maxilla: a preliminary report. J Oral Maxillofac Surg. 1991;49(12):1277-1287. 19. Misch CM, Misch CE, Resnik R, et al. Reconstruction of maxillary alveolar defects with mandibular symphysis grafts for dental implants: a preliminary procedural report. Int J Oral Maxillofac Implants. 1992;7(3):360-366. 20. Jensen J, Sinder-Pedersen S, Oliver AJ. Varying treatment strategies for reconstruction of maxillary atrophy with implants: results in 98 patients. J Oral Maxillofac Surg. 1994;52(3):210-218. 21. Misch CM, Misch CE. The repair of localized severe ridge defects for implant placement using mandibular bone grafts. Implant Dent. 1995;4(4):261-267. 22. Krauser JT, Rohrer MD, Wallace SS. Human histologic and histomorphometric analysis comparing Osteograf/N with Pepgen P-15 in the maxillary sinus elevation procedure: a case report. Implant Dentistry. 2000;9(4)298-302. 23. Smiler DG. Comparison of anorganic bovine mineral with and without synthetic peptide in a sinus elevation: a case study. Implant Dentistry. 2001;10(2)139-142. 24. Mellonig JT, Bowers GM, Bailey RC. Comparison of bone graft materials. Part I. New bone formation with autografts and allografts determined by Strontium-85. J Periodontol. 1981;52(6): 291-296. 25. Jarcho M. Calcium phosphate ceramics as hard tissue prosthetics. Clin Orthop Relat Res. 1981;67:259-278. 26. Froum SJ. Human histologic evaluation of HTR polymer and freeze-dried bone allograft. J Clin Periodontol. 1996;23(7):615-620. 27. Shapoff CA, Alexander DC, Clark AE. Clinical use of bioactive glass particulate in the treatment of human osseous defects. Compend Contin Educ Dent. 1997;18(4):352-358. 28. Sottosanti JS. Calcium sulfate: a biodegradable and biocompatible barrier for guided tissue regeneration. Compend Contin Educ Dent. 1992;13(3):226-234. 29. Sottosanti JS. Aesthetic extractions with calcium sulfate and the principles of guided tissue regeneration. Pract Periodontics Aesthet Dent. 1993;5(5):61-69. 30. Urist MR, Strates BS. Bone morphogenetic protein. J Dent Res. 1971; 50: 1392-1406. 31. Urist MR, Silverman BF, Büring K, et al. The bone induction principle. Clin Orthop Relat Res. 1967; 53:243-283. 32. Burwell RG. The function of bone marrow in the incorporation of a bone graft. Clin Orthop Relat Res. 1985; 71:125-141. 33. Callan DP, Rohrer MD. Use of bovine-derived hydroxylapatite in the treatment of edentulous ridge defects, a human clinical and histologic case report [published erratum in J Periodontal. 1993;64(9):923]. J Periodontol. 1993;64(6):575-582. 34. Petrungaro P. Platelet-rich plasma for dental implants and soft-tissue grafting [interview by Arun K. Garg]. Dent Implantol Update. 2001;12(6):41-46. 35. Petrungaro PS. Using platelet-rich plasma to accelerate soft tissue maturation in esthetic periodontal surgery. Compend Contin Educ Dent. 2001;22(9):729-746. 36. Petrungaro PS. Immediate restoration of dental implants in the aesthetic zone. Dent Implantol Update. 2001;12(12)89-95. 37. Marx RE, Garg AK. Bone graft physiology with use of PRP and hyperbaric oxygen. In: Jensen OT. The Sinus Bone Grafts. Chicago, IL: Quintessence Publishing Co; 1999. 38. Anitua E. Plasma rich in growth factors: preliminary results of use in the preparation of future sites for implants. Int J Oral Maxillofac Implants. 1999;14(4):529-535. 39. Garg AK. Bone Biology, Harvesting, Grafting for Dental Implants: Rationale and Clinical Applications. Chicago, IL: Quintessence Publishing, Co; 2004. * Founder, The Implant Learning Center, Lake Elmo, Minnesota; Private Practice in Periodontics and Implantology, Chicago, Illinois, and Lake Elmo, Minnesota Clinical and Radiographic Evaluation of Implant-Retained Mandibular Overdentures With Immediate Loading. Basic and Clinical Research Implant Dentistry. 16(2):212-223, June 2007. Assad, Ahmed S. BDS, MDSc, DDS *; Hassan, Susan A. BDS, MDSc, DDS +; Shawky, Yasser M. BDS, MDSc, DDS ++; Badawy, Magdy M. BDS, MDSc, DDS [S]
Abstract: Purpose: The aim of this study was to evaluate and compare immediate-loaded implant-retained mandibular overdentures and delayed-loaded implant-retained mandibular overdentures. Materials: Ten completely edentulous male patients received 40 dental implants. Patients were randomly divided into 2 equal groups, 5 patients each. Patients of both groups received conventional maxillary complete denture and had stage 1 surgery for placing 4 dental implant fixtures, 2 on each side anterior to the mental foramina. Group A: One-stage surgical procedure and immediate loading. Patients in this group received mandibular bar-retained overdenture supported by 4 endosseous implants loaded immediately after implant placement. Group B: The original 2-stage concept and delayed loading. Patients in this group received mandibular bar-retained overdenture supported by 4 endosseous implants that remained submerged for a period of 4 months before loading. The patients were evaluated clinically and radiographically immediately after overdenture delivery and after 6 months, 12 months, 18 months, and 24 months. Results: The results of clinical evaluation showed no statistical significant difference between the 2 groups regarding the effect of treatment. The radiographic assessment showed no statistical significant difference in mesial and distal alveolar bone loss at the different intervals of the follow-up period, except at the 12-month period, where immediately loaded implants showed a decrease in the amount of alveolar bone loss mesially and distally compared to delayed loaded implants. Conclusions: The results suggest that immediate-loaded implants provide promising results compared to delayed-loaded implants and can be a possible alternative procedure in implant dentistry. Histologic Comparison of Light Emitting Diode Phototherapy-Treated Hydroxyapatite-Grafted Extraction Sockets: A Same-Mouth Case Study. Basic and Clinical Research Implant Dentistry. 16(2):204-211, June 2007. Brawn, Peter R. DDS *; Kwong-Hing, Alan DDS, MSc + Abstract: Background: The stimulating effect of red and near-infrared (NIR) laser phototherapy on bone regeneration and growth has been shown in a number of in vitro and animal studies. However, the effect of NIR phototherapy on the bone regeneration of hydroxyapatite (HA) -treated extraction sockets has not been previously demonstrated. Materials and Methods: An investigational Biolux extraoral light emitting diode phototherapy device was used daily for 21 days postextraction and socket grafting with HA (Osteograf LD300) unilaterally. Bone regeneration of the phototherapy-treated and nontreated side wascompared in same-mouth extraction sockets. Results: Histologic evaluations showed enhanced bone formation and faster particle resorption associated with the phototherapy-treated socket graft compared with the non-phototherapy-treated socket. Conclusions: The accelerated bone healing in the phototherapy-treated HA socket graft may provide faster implant placement compared to nonorphototherapy-treated socket grafts. Peri-Implant Bone Regeneration With Calcium Sulfate: A Light and Transmission Electron Microscopy Case Report. Basic and Clinical Research Implant Dentistry. 16(2):195-203, June 2007. Scarano, Antonio DDS, MD *; Orsini, Giovanna DDS, PhD +; Pecora, Gabriele MD, DDS ++; Iezzi, Giovanna DDS, PhD [S]; Perrotti, Vittoria DDS, PhD [P]; Piattelli, Adriano MD, DDS | Abstract: Background: Calcium sulfate is a simple, biocompatible material with a very long, safe clinical history in several different fields of medicine. It is a rapidly resorbing material that leaves behind calcium phosphate lattice, which promotes bone regeneration. Objective: The aim of this study was a histological and ultrastructural evaluation of the tissues in a peri-implant site regenerated with calcium sulfate. Materials and Methods: The specimens were processed for observation under light and transmission electron microscopes. Results: In light microscopy, trabecular bone was present. No remnants of calcium sulfate were present. Transmission electron microscopy showed, in the areas of the interface with the implant surface, features of mature bone with many osteocytes. An amorphous layer and/or osteoid seam separated this mature bone from the metal surface. Conclusion: The results confirm the high biocompatibility and rapid resorption of calcium sulfate. Comparative Analysis of 4 Impression Techniques for Implants. Basic and Clinical Research Implant Dentistry. 16(2):187-194, June 2007. Cabral, Leonardo Moreira MS *; Guedes, Carlos Gramani DDS + Abstract: Purpose: This in vitro study investigated 4 impression techniques to determine their dimensional accuracy in comparison with a standard technique. Materials and Methods: A master metal framework with 2 inner hex implants (SIN; Sistema de Implante Nacional Ltda., Sao Paulo, Brazil) was used as a standard for the comparisons. Sixty master casts were prepared to evaluate 4 impression techniques: (1) indirect impression technique with tapered transfer copings, (2) direct impression technique with unsplinted squared transfer copings, (3) direct impression technique with squared transfer copings splinted with acrylic resin, and (4) direct impression technique with squared transfer copings with acrylic resin splints sectioned 17 minutes after setting and welded with the same resin. A profile projector was used to measure the distance between the copings attached to the analogs. Mean distances (mm) were calculated from 3 measurements for each sample in the master casts and in the master metal framework. Results: Analysis of variance and the Tukey HSD test were used for statistical analysis of data ([alpha] = 0.05). The results for the direct technique with squared transfer copings with acrylic resin splints sectioned and welded after setting were not significantly different from results for the master metal framework. Conclusion: Considering the methodology used and the results obtained, the direct impression technique with squared transfer copings with acrylic resin splints sectioned and welded after setting had better results than the other techniques studied. Clinical and Histological Evaluation of Immediate-Loaded Posterior Implants in Nonhuman Primates. Basic and Clinical Research Implant Dentistry. 16(2):176-186, June 2007. Suzuki, Jon B. DDS, PhD, MBA *; Misch, Carl E. DDS, MDS +; Sharawy, Mohamed BDS, PhD ++; Sarnachiaro, Oscar J. DDS [S]; Sarnachian, Guido O. DDS [//]; Mota, Luis DMD [P]; Arana, Gabriel DDS #; Gotta, Sergio L. DDS #; Gotta, Evangeline DDS #; Bui, Lynna DMD ** Abstract: Purpose: To evaluate a square-thread design implant and compare the bone-implant contact percentage between immediate- loaded and nonloaded implants (controls) in nonhuman primates. Materials: Five nonhuman primates each received 3 implants, with a total of 5 control implants and 10 immediate-loaded implants in posterior regions of the mouth. Ninety days after surgery (and function was appropriate), block sections of the implants were removed and sectioned in 200-[mu]m thick pieces. The block sections were stained with modified Masson for evaluation of the bone-implant contact percentage. Results: One of the immediate-loaded implants failed. The bone-implant contact percentage of control implants ranged from 50.34% to 64.13% and averaged 56.3%. The bone-implant contact percentage of immediate-loaded implants ranged from 43.23% to 75.72%, with an average of 62.4%. Two implants had lower bone-implant contact percentage than the others, and when these are not included in the evaluation, the bone-implant contact percentage average increased to 67.6%. Conclusions: Immediate-loaded implants in the nonhuman primates often have a higher bone-implant contact percentage at 90 days than unloaded implants. The bone remodeling is different for loaded implant-bone interfaces than for unloaded conditions. However, 1 immediate-loaded implant failed, and 2 implants had lower bone-implant contact percentage than controls. Therefore, although there are benefits of immediate loading, there appear to also be some risks. Factors Influencing the Preservation of the Periimplant Marginal Bone. Clinical Science and Techniques Implant Dentistry. 16(2):165-175, June 2007. Hermann, Frederic DDS *; Lerner, Henriette DDS +; Palti, Ady DDS ++ Abstract: Esthetic outcomes cannot be attributed to a single parameter. Rather, as this article shows, they are the result of a number of important factors, especially in the esthetic zone. An understanding of the meaning of biologic width, of the integration of the platform-switching concept into implant treatment facilitates the preservation of a stable marginal bone level around the implant neck. This stable bone then serves to support the soft tissue, determining the long-term esthetic and functional treatment outcomes stability. The following points should be noted: (1) A prefabricated post that can be used both as a temporary post and as the definitive abutment helps to avoid a frequent replacement of secondary components, provided that the 3-dimensional position of the implant is correct. It prevents a repeated destruction of the connective-tissue attachment on the biologic width, which would carry with it the risk of bone resorption. (2) A special implant and abutment design (a ledge and integration of the biologic width/tapered shape of the post) facilitates nonsurgical lengthening and thickening of the periimplant soft tissue. This leads to the establishment of a wider and more resistant zone of connective tissue. (3) A microrough and nanorough titanium surface extending to the implant shoulder in conjunction with the platform-switching concept provides osseous integration along the entire length of the implant. A fine thread optimally distributes the masticatory forces in the region of the implant neck, avoiding further bone loss in this region. Immediate Provisionalization on a New Implant Design for Esthetic Restoration and Preserving Crestal Bone. Clinical Science and Techniques Implant Dentistry. 16(2):155-164, June 2007. Guirado, Jose Luis Calvo DDS, PhD *; Yuguero, Maria Rosario Saez DDS, PhD +; Zamora, Guillermo Pardo DDS, PhD ++; Barrio, Emilio Munoz DDS, PhD [S] Abstract: Purpose: This article describes how the concept of platform switching has been incorporated into a new implant design as a method of reducing crestal bone loss and maintaining the gingival papillae. A 6-month study of the effects of this implant on bone loss is described. Materials: Ten new platform switched implants were placed into fresh anterior maxillary extraction sites in 3 men and 7 women, ranging in age between 29 and 45 years old, and immediately provisionalized. The adjoining bone height was evaluated with digital radiography on the day after implant placement, and at 15 days, 1, 2, 3, and 6 months later. Results: After 6 months, the mean bone loss on the mesial of the central-incisor implants was 0.05 mm. The mean bone loss was 0.07 mm on the distal of the central incisor implants, 0.07 mm on the mesial of the lateral-incisor implants, and 0.06 mm on the distal of the lateral-incisor implants. Conclusions: An implant design that incorporates the concept of platform switching is a simple and effective way to control circumferential bone loss around dental implants, helping to ensure a predictable esthetic result Implants in Conjunction With Removable Partial Dentures: A Literature Review. Clinical Science and Techniques Implant Dentistry. 16(2):146-154, June 2007. Mijiritsky, Eitan DMD Abstract: Although the benefits of implant-borne removable prostheses are readily apparent for the fully edentulous patient and have been well documented, there is a paucity of studies concerning the combination of implants with removable partial dentures in partially edentulous patients. The aim of this article is to review the literature regarding implants with removable partial dentures and evaluate the evidence for this clinical approach. A MEDLINE/PubMed search from 1990 to 2006, focusing on the use of implants with removable partial dentures and related features, was supplemented with a hand search to identify relevant peer-reviewed English articles published in dental journals and textbooks on removable partial dentures. A New Atraumatic System for Tooth Removal and Immediate Implant Restoration. Clinical Science and Techniques Implant Dentistry. 16(2):139-145, June 2007. Babbush, Charles A. DDS, MScD Abstract: Methods for extracting teeth have remained remarkably static over the decades, with trauma to the surrounding tissues continuing to be a common occurrence. This article reviews the mechanisms involved in traditionally extracting teeth,and discusses a technological breakthrough that enables nonmolar intact teeth to be extracted mechanically and atraumatically. The benefits of using this technology include preservation of the adjacent papillae and underlying host bone, along with dramatically improved patient experiences. Teeth that are extracted with an innovative system may be immediately replaced with implants. Lingual Vascular Canals of the Mandible: The Risk of Bleeding Complications During Implant Procedures. Clinical Science and Techniques Implant Dentistry. 16(2):131-138, June 2007. Longoni, Salvatore MD, DDS; Sartori, Matteo DDS, DIU; Braun, Marc MD; Bravetti, Pierre DDS; Lapi, Antonio DDS; Baldoni, Marco MD, DMD; Tredici, Giovanni MD Abstract: Purpose: The aim of this article is to investigate the potential risk of a critical life-threatening hemorrhage due to the perforation of the lingual cortical plate and arterial trauma of the terminal branches of the sublingual artery. In fact, in many cases, implants are placed in the mandibular interforaminal region, and this area is also often involved in oral surgery as a bone donor site. Materials and Methods: One hundred dry skull Caucasian mandibles and 100 computed tomographies (CTs) of the mandible of Caucasian patients were examined. The entrances of the lingual vascular canalswere analyzed. Positions and dimensions of the entrances are reported. Results: In 80% of the dry skull mandibles, at least 1 lingual canal was found, and the CT scan detected the presence of at least 1 lingual vascular canal in up to 60% of patients. Conclusions: A CT examination should routinely be performed before any surgical approach to the interforaminal region. Computer-Aided Design/Computer-Aided Manufacturing Surgical Guidance for Placement of Dental Implants: Case Report. Clinical Science and Techniques Implant Dentistry. 16(2):123-130, June 2007. Wong, Natalie Y. DDS *; Huffer-Charchut, Heather DMD +; Sarment, David P. DDS, MS ++ Abstract: Dental implant rehabilitation faces increasing prosthetic and esthetic demands, requiring precise surgical planning and placement. Presurgical treatment evaluation can now be accomplished using 3-dimensional computed tomography imaging. Although software has been developed to assist in implant selection and localization, transferring this information to the surgical field has remained a difficult task. Over the last few years, computer-aided design and manufacturing have made it possible to use data from computed tomography in order to transfer virtual implant placementto the surgery. One of these techniques utilizes a small computer-driven drilling mechanism that transfers implant planning on a laboratory model. This novel approach may be advantageous once available in dental laboratories and/or offices. This report presents the method and, for the first time, illustrates it with a fully edentulous advanced clinical case. Resulting clinical benefits over traditional procedures are discussed. Bifid Mandibular Canal in Japanese. Clinical Science and Techniques Implant Dentistry. 16(1):24-32, March 2007. Naitoh, Munetaka DDS, PhD *; Hiraiwa, Yuichiro DDS +; Aimiya, Hidetoshi DDS +; Gotoh, Masakazu DDS ++; Ariji, Yoshiko DDS, PhD [S]; Izumi, Masahiro DDS, PhD [//]; Kurita, Kenichi DDS, PhD [P]; Ariji, Eiichiro DDS, PhD ** Abstract: The location and configuration of mandibular canal variations are important in surgical procedures involving the mandible, such as extraction of an impacted third molar, dental implant treatment, and sagittal split ramus osteotomy. We report 3 Japanese patients with bifid mandibular canals using panoramic radiograph and multi-slice helical computed tomography (CT) images. In 2 of the 5 sides, the bifid mandibular canal was suggested on panoramic radiograph. The bifid mandibular canal had a short and narrow upper canal toward the distal area of the second molar in 4 sides, and a short and narrow lower canal toward the distal area of second molar in 1 side, as revealed on reconstructed CT images. Since the location and configuration of mandibular canal variations are important in surgical procedures involving the mandible, they should be carefully observed using reconstructed CT images. Medical Contraindications to Implant Therapy: Part II: Relative Contraindications. Clinical Science and Techniques Implant Dentistry. 16(1):13-23, March 2007. Hwang, Debby DMD *; Wang, Hom-Lay DDS, MSD + Abstract: Systemic conditions and habits influence dental implant survival to varying degrees. Illnesses that impair the normal healing cascade worsen surgical success. The mere presence of a disease, however, does not necessarily preclude implant therapy or affect significantly long-term outcomes. Certain disorders, when controlled, or other situations allow implant survival rates that match those in health. This paper reviews these relative contraindications, which include adolescence, aging, osteoporosis, smoking, diabetes, positive interleukin-1 genotype, human immunodeficiency virus positivity, cardiovascular disease, and hypothyroidism. Multitier Technique for Bone Augmentation Using Intraoral Autogenous Bone Blocks. Clinical Science and Techniques Implant Dentistry. 16(1):5-12, March 2007. Schwartz-Arad, Devorah DMD, PhD *; Levin, Liran DMD + Abstract: Purpose: Intraoral bone grafts are a convenient and acceptable source of autogenous bone for alveolar reconstruction due to bone origin similarity and less morbidity. In large bone defects, 1 tier might be insufficient to achieve the desired bone shape. The purpose of this article was to describe a multitier technique for reconstruction of extensive bone deficiency, using only intraoral block bone grafts for implant site augmentation. Materials: After clinical and radiographic evaluation of the recipient site, measurements were taken to determine the size of the bone deficiency. The first tier of bone graft was harvested from the mandibular ramus. After additional clinical and radiographic evaluation of the recipient site 5 months later, bone graft blocks for the second tier were harvested either from the second ramus or the mandibular symphysis. Conclusions: A new technique, the multitier intraoral bone block graft, for the future use of dental implants, is described. This technique can serve as an optional operation procedure for extensively atrophic alveolar bone augmentation. Mineralized Bone Allograft-Plug Socket Augmentation: Rationale and Technique. Clinical Science and Techniques Implant Dentistry. 16(1):33-41, March 2007. Wang, Hom-Lay DDS, MSD *; Tsao, Yi-Pin DDS, MS + Abstract: Background: Socket augmentation allows clinicians to preserve alveolar bone height. This, in turn, could maintain adjacent soft tissue (papillae) height to promote optimal implant esthetics. Materials and Methods: A new regimen for the socket augmentation technique (the mineralized bone allograft-plug technique) is introduced. It uses solvent-preserved mineralized cancellous allografts to fill the sockets up to 1-2 mm below the bone crest. This is covered with a bioabsorbable collagen wound dressing (CollaPlug(R); Zimmer Dental, Carlsbad, CA). Illustrations to demonstrate the technique are introduced. A case treated with this approach is presented. Results: This technique is easy to perform with minimal trauma. Both clinical observation and histological results showed excellent bone formation. Conclusion: Our clinical experience, as well as histologic data, suggest that the mineralized bone allograft-plug is a suitable technique for socket augmentation. A Histomorphogenic Analysis of Bone Grafts Augmented With Adult Stem Cells. Basic and Clinical Research Implant Dentistry. 16(1):42-53, March 2007. Smiler, Dennis DDS, MScD *; Soltan, Muna DDS +; Lee, Joseph W. MBA ++ Abstract: Purpose: To evaluate the influence of bone marrow aspirate added to xenograft or alloplast graft matrix scaffold to produce bone. Materials: A maximum of 4 cc bone marrow was aspirated from the anterior iliac crest of 5 patients to saturate the matrix scaffold prior to bone graft. Seven graft sites evaluated included sinus lift augmentation, particulate onlay graft of the maxilla via a tunneling procedure, and particulate onlay graft of the maxilla stabilized with titanium mesh. The xenograft scaffold was either PepGen Putty (DENTSPLY Friadent CeraMed, Lakewood, CO) or C-Graft resorbable algae material (Clinician's Preference, Golden, CO). The alloplast scaffold was [beta]-tricalcium phosphate (either Curasan AG, Kleinostheim, Germany, or Vitoss; Malvern, PA). Results: Graft sites healed for 4-7 months. Core specimens of graft sites were taken with trephine drills, and submitted for standard histologic and histomorphogenic analysis. The percentage of graft material converted into bone, percentage of vital graft matrix, percentage of unresorbed matrix, and percentage of remaining interstitial tissue were measured. After a 4-month healing of sinus-lift augmentation with C-Graft, the biopsy showed 31% bone that was 100% vital. Unresorbed graft material was 26%, and remaining interstitial material constituted 43%. Using pure phase [beta]- tricalcium phosphate, a 4-month core biopsy showed 40% bone that was 100% vital. Residual graft was 3% and interstitial material 57%. A sinus grafted with PepGen P-15 (DENTSPLY Friadent CeraMed) was found to be 14% bone, with 100% of that bone vital. The non-bone within the core was 36%. After a 4 1/2-month healing of bilateral sinus grafts using a nonpure phase [beta]-tricalcium phosphate, the percentage of the biopsy that was bone was 23% on the right side and 16% on the left side. Vital bone was 89% (right side) and 86% (left side). The core taken after 4 months of healing from the anterior maxilla particulate onlay graft with PepGen P-15 showed 32% bone, with 100% found to be vital. Non-bone within the core was 15%, and 53% was interstitial material. After 7 months of healing, a biopsy core from the maxillary ridge augmented with C-Graft was 45% newly formed bone, with 100% of the bone vital. There was no residual graft material present. Discussion: Bone regeneration by cell-based strategies depends upon an understanding of the biology and potential of adult stem cells as a method of regenerating bone. Conclusions: Bone marrow aspirate containing adult stem cells when mixed with bioengineered graft materials provide a scaffold to support the proliferation, differentiation, and maturation of the stem cells, as well as facilitating angiogenesis. This article presents histological evidence that stem cells aspirated from bone marrow and transplanted onto biocompatible scaffolds can successfully regenerate bone. This new standard for bone grafting may emerge as an alternative to autogenous bone grafts. Aesthetics in Oral Implantology: Biological, Clinical, Surgical, and Prosthetic Aspects. Basic and Clinical Research Implant Dentistry. 16(1):54-65, March 2007. Sammartino, Gilberto MD, DDS *; Marenzi, Gaetano DMD, PhD +; di Lauro, Alessandro Espedito DMD, PhD ++; Paolantoni, Guerino DMD [S] Abstract: Objectives: The aim of this study was to identify a correct clinical, surgical, and prosthetic management of endosseous implants replacing missing teeth in the anterior maxilla, achieving predictable aesthetic outcomes. Placement of immediate post-extraction implants without incisions or flap elevation is one of the surgical treatment options able to improve the healing and regenerative potentials of the fresh socket. Materials: Fifty-five patients (33 men, 22 women), ranging in age from 19 to 57 years (mean 29), were selected for this study. All the patients were not smokers, no bruxers, presented stable soft tissue conditions, an acceptable occlusion, and the absence of pathologies that would contraindicate bone healing. Patients were treated with implants made by 2 manufacturers: Institute Straumann, Walderburg, Switzerland and Friadent, Mannheim, Germany. A total of 87 implants were placed immediately after each failing tooth had been removed. The temporary restoration was placed 3 months after implant place-ment, and the final restoration was placed 4 months from the surgical procedure. The patients were evaluated clinically and radiographically at implant placement, and 2, 4, 18, and 24 months post-insertion. Results: At 24 months, only 3 implants were lost (2 in male patients;1 in female patient). All of these failed implants did not achieve osseointegration. The overall success rate was 96.6%, with an implant failure rate of 3.4%, all prior to restoration. Conclusions: The immediate placement in the anterior maxilla fresh extraction sockets without incisions or flaps elevation is a surgical option that can ensure ideal peri-implant tissues healing, preserving the presurgical gingival and bone aspects. For a predicable aesthetic result, the most important aspect seems to be the height and thickness of the buccal bone wall, which remain after immediate placement of the fixture. The Integration of Chitosan-Coated Titanium in Bone: An In Vivo Study in Rabbits. Basic and Clinical Research Implant Dentistry. 16(1):66-79, March 2007. Bumgardner, Joel D. PhD *; Chesnutt, Betsy M. MS +; Yuan, Youling PhD ++; Yang, Yunzhi PhD ++; Appleford, Mark MS +; Oh, Sunho PhD [S]; McLaughlin, Ronald DVM [//]; Elder, Steven H. PhD [P]; Ong, Joo L. PhD # Abstract: Procedure: Much research is directed at surface modifications to enhance osseointegration of implants. A new potential coating is the biopolymer, chitosan, the deacetylated derivative of the natural polysaccharide, chitin. Chitosan is biocompatible, degradable, nontoxic, and exhibits osteogenic properties. The aim of this research was to investigate the hypothesis that chitosan-coated titanium supports bone formation and osseointegration. Materials and Methods: Chitosan (1wt% of 92.3% deacetylated chitosan in 1% acetic acid) was solution cast and bonded to rough ground titanium pins (2-mm diameter x 4-mm long) via silane reactions. Calcium phosphate sputter-coated titanium and uncoated titanium pins were used as controls. Two chitosan-coated pins, and 1 each of calcium phosphate coated and uncoated pins were implanted unilaterally in the tibia of 16 adult male New Zealand white rabbits. At 2, 4, 8, and 12 weeks, undecalcified sections were histologically evaluated for healing and bone formation. Results: Histological evaluations of tissues in contact with the chitosan-coated pins indicated minimal inflammatory response and a typical healing sequence of fibrous, woven bone formation, followed by development of lamellar bone. These observations were similar to those for tissues interfacing the control calcium phosphate-coated and uncoated titanium implants. Quantitative comparisons of the bone-implant interface were not possible since 31% of the implants migrated into the tibial marrow space after implantation due to insufficient cortical bone thickness to hold pins in place during healing. Conclusion: These data support the hypothesis that chitosan-coatings are able to develop a close bony apposition or the osseointegration of dental/craniofacial and orthopedic implants. Effect of Tumor Necrosis Factor-[alpha] Gene Polymorphism on Peri-Implant Bone Loss Following Prosthetic Reconstruction. Basic and Clinical Research Implant Dentistry. 16(1):80-88, March 2007. Cury, Patricia R. PhD *; Joly, Julio Cesar PhD *; Freitas, Nivea MSc +; Sendyk, Wilson R. PhD ++; Nunes, Fabio Daumas DDS, PhD [S]; de Araujo, Ney S. PhD [//] Abstract: Purpose: The present study investigates the association between a specific polymorphism in the tumor necrosis factor (TNF)-[alpha] gene, consisting of allele 2 of TNF-[alpha]-308, and peri-implant bone loss following prosthetic reconstruction. Materials and Methods: This case-control study included 36 patients (20 women, 16 men; mean age 46 years) who had used implant-supported prostheses for a minimum of 6 months and a maximum of 31 months. The patients were nonsmoking, white Caucasian Brazilians, in good general health, and were not receiving medication. In the case group, patients exhibited 1 or more implants with a diagnosis of peri-implant bone loss following prosthetic reconstruction; control patients had 1 or more healthy implants. Results: Polymorphism in the TNF-[alpha] gene, allele 2 of TNF-[alpha]-308, was not associated with an increased risk for peri-implant bone loss following prosthetic reconstruction (P = 0.19; [chi]2 = 1.71; df = 1), although 21.1% of the subjects carried allele in the control group 2, and 41.2% carried allele 2 in the case group. Conclusions: Polymorphism in allele 2 of the TNF-[alpha]-308 gene is not associated with an increased risk for peri- implant bone loss following prosthetic reconstruction. However, further studies based on a greater number of patients are necessary. Antibacterial Effect of Zinc Phosphate Mineralized Guided Bone Regeneration Membranes. Basic and Clinical Research Implant Dentistry. 16(1):89-100, March 2007. Chou, Alex H. K. DMD, MS *; LeGeros, Racquel Z. PhD +; Chen, Zhou DDS, MS, PhD ++; Li, Yihong DDS, MPH, Dr.PH [S] Abstract: Purpose: Current commercial guided bone regeneration membranes are susceptible to bacterial colonization, leading to premature membrane degradation. The purpose of this research is to modify current resorbable guided bone regeneration membranes with antibacterial property by mineralizing with zinc phosphate. Materials: Resolut Adapt LT (Gore-Tex; W.L. Gore & Associates, Inc., Flagstaff, AZ), composed of copolymer PGA/TMC, and BioMend Extend (Zimmer Dental, Carlsbad, CA), composed of bovine type 1 collagen, were used. The membranes were mineralized with zinc phosphate. The mineralized membranes were characterized using scanning electron microscopy, energy dispersive spectroscopy, x-ray diffraction, Fourier transform infrared spectroscopy, inductive coupled plasma, and thermogravimetry. Antibacterial property of zinc phosphate mineralized and nonmineralized membranes were determined using Actinobacillus actinomycetemcomitans standard strain ATCC 29522. Results: Scanning electron microscopy, energy dispersive system, and Fourier transform infrared identified zinc phosphate in the zinc phosphate mineralized membranes. Zinc phosphate mineralized membranes showed significant reduction in bacterial colony, forming units compared to nonmineralized membranes. Conclusion: Results of this study suggest that the use of zinc phosphate mineralized membranes can inhibit oral bacterial colonization and prevent inflammation due to membrane exposure. This antibacterial property may help achieve the optimal goal of guided bone regeneration. Genotoxicity of Corrosion Eluates Obtained From Endosseous Implants. Basic and Clinical Research Implant Dentistry. 16(1):101-109, March 2007. Ribeiro, Daniel Araki DDS, PhD *; Matsumoto, Mariza Akemi DDS, PhD +; Padovan, Luis Eduardo Marques DDS, PhD +; Marques, Mariangela Esther Alencar MD, PhD ++; Salvadori, Daisy Maria Favero BMD, PhD [S] Abstract: Purpose: Commercially pure titanium alloys are currently used as metallic biomaterials in implantology. Corrosion phenomena appear to play a decisive role in metallic implant long-term behavior. Thus, the goal of this study was to examine the genotoxic potential of corrosion eluates obtained from dental implants using Chinese ovary hamster cells in vitro by the single-cell gel (comet) assay. This technique detects deoxyribonucleic acid strand breaks in individual cells in alkaline conditions. Materials and Methods: The materials tested included 3 dental implants commercially available. Each of the tested materials was corroded in a solution consisting of equal amounts of acetic acid and sodium chloride (0.1 M) for 1, 3, 7, 14, and 21 days. The Chinese ovary hamster cultures were then exposed to all corrosion eluates obtained from endosseous dental implants for 30 minutes at 37[degrees]C. Results: None of the eluates was found to exhibit genotoxicity, regardless of the type of dental implant used. Conclusion: The results suggest that all dental implants tested in this study did not induce deoxyribonucleic acid breakage as depicted by the single-cell gel (comet) assay. Knowledge, Attitude, and Practice of Dental Implantology in Nigeria. Basic and Clinical Research Implant Dentistry. 16(1):110-118, March 2007. Akeredolu, Patricia A. BDS, FMCDS *; Adeyemo, Wasiu L. BDS, Dr. Med. Dent. +; Gbotolorun, Olalekan M. BDS +; James, Olutayo BDS ++; Olorunfemi, Babatunde O. BDS, Msc [S]; Arotiba, Godwin T. BDS [//] Abstract: Aim: The purpose of this study was to assess the knowledge, attitude, and practice of dental implantology among dentists practicing in Nigeria. Materials: Self-administered questionnaires to assess the knowledge, practice, and attitude of dental implantology were sent to dentists practicing in all the 6 geopolitical zones of Nigeria (i.e., all tertiary dental institutions, and selected general and private hospitals within the zones). Data collected were analyzed and presented in descriptive and tabular forms. Results: The response rate was 77%. Only 2 (1.3%) of the respondents claimed to have employed implant(s) for dental restoration in their practice, while 152 respondents (98.7%) have never used implants as a method of tooth/teeth restoration. Of the latter, 46.1% have suggested implants for full/partial denture patients, 31.8% have suggested dental implants to patients needing single-tooth replacement, and 89.6% were ready for dental implant placement if equipment and materials for dental implants backed up with adequate training were provided. Of respondents, 83.1% also believed that implantology is a multidisciplinary approach, and 42.9% rated implants as the best option for dental restoration. Conclusions: The practice of implant dentistry is presently very low in Nigeria. Clearly, there is a need for dental implant education for Nigerian dentists to increase their knowledge and proficiency in dental implant dentistry. In addition, all efforts should be made to include implant education and practice in dental curricula in undergraduate and postgraduate institutions in Nigeria.