Scott D. Ganz

Use of cone beam computed tomography in implant dentistry: the International Congress of Oral Implantologists consensus report.

Purpose: The International Congress of Oral Implantologists has supported the development of this consensus report involving the use of Cone Beam Computed Tomography (CBCT) in implant dentistry with the intent of providing scientifically based guidance to clinicians regarding its use as an adjunct to traditional imaging modalities. Materials and Methods: The literature regarding CBCT and implant dentistry was systematically reviewed. A PubMed search that included studies published between January 1, 2000, and July 31, 2011, was conducted. Oral presentations, in conjunction with these studies, were given by Dr. Erika Benavides, Dr. Scott Ganz, Dr. James Mah, Dr. Myung-Jin Kim, and Dr. David Hatcher at a meeting of the International Congress of Oral Implantologists in Seoul, Korea, on October 6–8, 2011. Results: The studies published could be divided into four main groups: diagnostics, implant planning, surgical guidance, and postimplant evaluation. Conclusions: The literature supports the use of CBCT in dental implant treatment planning particularly in regards to linear measurements, three-dimensional evaluation of alveolar ridge topography, proximity to vital anatomical structures, and fabrication of surgical guides. Areas such as CBCT-derived bone density measurements, CBCT-aided surgical navigation, and postimplant CBCT artifacts need further research. ICOI Recommendations: All CBCT examinations, as all other radiographic examinations, must be justified on an individualized needs basis. The benefits to the patient for each CBCT scan must outweigh the potential risks. CBCT scans should not be taken without initially obtaining thorough medical and dental histories and performing a comprehensive clinical examination. CBCT should be considered as an imaging alternative in cases where the projected implant receptor or bone augmentation site(s) are suspect, and conventional radiography may not be able to assess the true regional three-dimensional anatomical presentation. The smallest possible field of view should be used, and the entire image volume should be interpreted.

Implant treatment planning using a patient acceptance prosthesis, radiographic record base, and surgical template. Part 1: Presurgical phase.

The use of a patient acceptance prosthesis as a radiographic record base after incorporation of a radiopaque medium to optimize information from computed tomography scans for implant planning and prosthodontic design is presented. The patient acceptance prosthesis can also be used as a surgical template. By receiving the patients acceptance of the prosthesis before computed tomography scans are done, the potential for success is increased.

Use of cone beam computed tomography and a laser intraoral scanner in virtual dental implant surgery: part 1.

Objective:To describe a new procedure capable of coupling 2 data sets from cone beam computed tomography (CBCT) and an intraoral laser digital scanner to produce a stereolithographic model and surgical guide. Methods:Use of DICOM (digital imaging and communications in medicine) format data obtained from CBCT scan images merged with standard triangulation language (STL) file data obtained from digital impressions using an intraoral laser scanner. The 2 data sets were electronically sent to a 3-dimensional imaging and technology software company over the Internet to fabricate a stereolithographic model of the jaws and surgical guide without the use of stone or plaster models obtained from traditional dental impressions. Conclusion:STL file data are able to accurately fabricate a stereolithographic model and surgical guide for implant surgery.

Use of an Intraoral Laser Scanner During the Prosthetic Phase of Implant Dentistry: A Pilot Study

The accuracy of a digital impression technique to fabricate the implant restoration and abutment for a dental implant using an intraoral laser scanner was evaluated in 36 patients who were missing a single posterior tooth in either the mandible or maxilla that was restored with a single implant. The spatial position of each integrated implant, including the surrounding anatomic hard and soft tissues of adjacent structures, was captured utilizing a special scanning abutment with an intraoral laser scanner. Data from the scanning protocol was then delivered via the Internet in the form of an STL file to the manufacturing site for the production of a custom computer-aided design abutment and crown. All 36 restorations and abutments were delivered to the patients and evaluated for marginal integrity, interproximal contact points, and occlusion. Of the 36 patients, 6 required contact adjustments, 7 required occlusal adjustments, and 3 required a gingivectomy around the implant to completely seat the restoration. Chair time for adjustments did not exceed 15 minutes. The findings suggest that an intraoral laser scanner can be used with confidence to obtain consistent and accurate digital impressions to fabricate custom restorations and abutments for dental implants.

Full-mouth rehabilitation with immediate loading of implants inserted with computer-guided flap-less surgery: a 3-year multicenter clinical evaluation with oral health impact profile.

Objective:The purpose of this report is to present the clinical outcomes and patients’ satisfaction of full-mouth rehabilitation using computer-aided flapless implant placement and immediate loading of a prefabricated prosthesis. Materials and Methods:The study included 30 consecutive fully edentulous patients who received 312 implants. Mandible and maxilla were treated in the same surgical session with computer-guided flapless approach using the NobelGuide protocol. Prefabricated screw-retained fixed prostheses were inserted at the end of surgery. Clinical and radiographic evaluations were assessed at 6, 12, and 36 months. At baseline and 6 months after surgery, patients answered Oral Health Impact Profile in Edentulous Adults questionnaire to assess satisfaction. Results:The implant survival rate was 97.9%, whereas the average marginal bone loss was 1.9 ± 1.3 mm after 3 years. At 6 months, patients showed significantly greater satisfaction with their fixed rehabilitation when compared with conventional dentures. Conclusions:The results of this study confirm that rehabilitation with a prefabricated fixed prosthesis supported by implants placed with NobelGuide protocol is a viable and predictable treatment and increases patients’ satisfaction and improves oral health-related quality of life.

Resistance to crown displacement on a hexagonal implant abutment.

The purpose of this study was to evaluate the resistance and retention of a hexagonal abutment to crown displacement with varying crown heights (10, 12, and 14 mm) and axis of load. Implants were embedded in resin blocks at a 30° angle to the vertical. Crowns were made at heights of 10, 12, and 14 mm. Groups of 5 crowns for each of the 3 crown heights were loaded (200 N) both under the long axis and off axis. The marginal gaps were measured using standardized periapical radiographs before and after loading. The gaps were statistically compared using a 3-way analysis of variance with factors of load, crown height, and point of load. Crowns were loaded to 106 cycles or point of fail ure. The 10-mm crowns did not show any displacement. The 12-mm and 14-mm groups only showed displacement of the off axis-loaded crowns. The average marginal displacement was 193.56 μ (standard deviation [SD] ± 138.62 μ) at point of failure (320,717 cycles) and 400.18 μ (SD ± 644.31) at point of failure (134,278 cycles), respectively. A 1-piece implant with a standardized abutment design can provide sufficient resistance and retention form for crowns of varying dimension if loads are centered over the long axis of the crown.

The replacement of a unilateral partial denture with an implant-supported fixed prosthesis: a clinical report.

Various treatment options have been advocated to restore short span edentulous spaces. For a single edentulous space, some clinicians have advocated the use of a unilateral removable partial denture because this design has certain advantages for the patient, and it does not require the preparation of adjacent teeth for the fabrication of a fixed partial denture. However, potentially serious consequences associated with this design type have been reported. The unilateral partial denture can become dislodged, swallowed, or aspirated, which can result in hospitalization, perforation of the gastrointestinal tract, possibly followed by surgical intervention to retrieve the prosthesis. Although an implant-supported single tooth replacement has been widely accepted and documented as a predictable treatment alternative, few clinical cases present have been presented in which potential severe iatrogenic damage can be so easily avoided. A treatment alternative that avoids potential hazards inherent in the design of a unilateral partial denture has been presented in this article.

Rehabilitation of Full-Mouth Edentulism: Immediate Loading of Implants Inserted With Computer-Guided Flapless Surgery Versus Conventional Dentures: A 5-Year Multicenter Retrospective Analysis and OHIP Questionnaire.

Objective: The purpose of this report is to compare satisfaction of patients rehabilitated with full-mouth fixed prostheses using computer-aided flapless implant placement and immediate loading with patients rehabilitated with conventional removable prostheses. Materials and Methods: The study included 30 consecutive fully edentulous patients who received 312 implants and 30 matched controls treated with conventional removable prostheses. Mandible and maxilla were treated in the same surgical session with computer-guided flapless approach using NobelGuide protocol. Prefabricated screw-retained fixed prostheses were inserted at the end of surgery. Clinical and radiographic evaluations were assessed at 6, 12, and 36 months. At baseline and 5 years after prostheses delivery, patients answered OHIP-EDENT questionnaire (Oral Health Impact Profile for Edentulous subjects) to assess satisfaction. Results: The implant survival rate was 97.9%, whereas the average marginal bone loss was 1.9 ± 1.3 mm after 3 years. At 6 months, patients showed significantly greater satisfaction with their fixed rehabilitation as compared to conventional dentures. Conclusions: The results of this study confirm that rehabilitation with a prefabricated fixed prosthesis supported by implants placed with NobelGuide protocol significantly increases the quality of life in fully edentulous patients when compared with complete dentures.