International Journal of Periodontics & Restorative Dentistry, 01/1997

This 16-week open-label study assessed the safety and technical feasibility of implanting human recombinant bone morphogenetic protein-2 delivered on an absorbable collagen sponge (rhBMP-2/ACS) for two-stage maxillary floor sinus augmentation. This first use of rhBMP-2/ACS in human clinical maxillary sinus floor augmentation included 12 patients with inadequate bone height in the posterior maxilla. The total delivered dose of rhBMP-2 implanted varied from 1.77 to 3.40 mg per patient. the rhBMP-2/ACS device was easily handled. Significant bone growth was documented by computerized tomographic scans in all evaluable patients (11/12). The overall mean height response for the maxillary sinus floor augmentation was 8.51 mm (95% confidence interval 6.07 to 10.95). There were no serious or unexpected immunologic or adverse effects and no clinically significant changes in complete blood counts, blood chemistries, or urinalysis results. The most frequent adverse effects were facial edema, oral erythema, pain, and rhinitis. Eleven patients have received dental implants and follow-up examinations are still being conducted. Histologic examinations of core bone biopsies obtained at the time of dental implant placement confirmed the quality of the bone induced by rhBMP-2/ACS. These results tend to indicate that rhBMP-2/ACS may provide an acceptable alternative to traditional bone grafts and bone substitutes for maxillary sinus floor augmentation procedures in humans.

This study reports the successful use of osseointegrated implants to replace posterior teeth combined with the autogenous bone graft technique in the sinus. Preliminary data (1 to 6 years experience) of this one-stage procedure are presented. A total of 33 patients were treated - 44 sinus grafts were augmented with bone from the anterior iliac crest. Reconstruction was completed with ceramic fixed partial dentures, and there was a follow-up of 3 to 80 months (mean 40.2 months) after loading. None of the 44 sinus grafts was lost. Of the 121 implants placed, eight failed, resulting in a failure rate of 6.6% and a cumulative failure rate of 6.8%. Of the 44 prostheses placed in the 44 sinuses, one failed, resulting in a prosthesis stability of 97.7%. Complications were encountered in three patients (three sinuses, eight implants); treatments were administered, symptoms subsided, and the implants integrated in two patients (two sinuses, six implants). One patient lost the two implants and the prosthesis, but the graft integrated. No other complications have since occurred. The results compare favorably with previous reports in terms of implant survival and stability. The implant survival rate approached that of implants placed in uncompromised maxillary bone.

Three cases are presented where early exposure of a resorbable membrane occurred during guided tissue regeneration therapy. An antimicrobial regimen was selected to determine whether infection of exposed membranes could be controlled to the point of achieving acceptable clinical results without membrane removal. The results suggest that with the use of the antimicrobial regimen: (1) exposure is compatible with successful clinical results, and (2) removal is not necessary.

This article present a surgical technique to promote bone regeneration and enlargement of localized alveolar ridge defects in the mandible. The purpose of this study was to investigate the use of spacemaking gold frames used in combination with expanded polytetrafluoroethylene Gore-Tex augmentation membranes (WL Gore) on two patients to create and maintain adequate space for the regeneration of bone. The membrane was sutured under the frame and the assembly was bent and adapted over the residual bony defect to create a dome and prevent the expanded polytetrafluoroethylene barrier membranes from collapsing into the defects. The framed membranes have also been positioned over dehisced implants. After a healing period of 12 months, a second-stage surgery procedure was performed to remove the gold frames and expanded polytetrafluoroethylene membranes and to connect the healing abutments. The gain of bone dimension was assessed by standardized measurements. On both patients the spaces created by the framed membranes were completely filled with newly regenerated bone. Biopsies from the treated sites revealed new bone formation.

The principle of guided tissue regeneration by barrier membranes to restore lost periodontal tissue around natural teeth has also been used around osseointegrated implants in an attempt to restore alvolar ridge defects. While most periodontal procedures in the literature describe root coverage by mucoginigval surgery, which achieves healing through soft tissue attachment, regeneration of denuded root surfaces is performed by guided tissue regeneration using expanded polytetrafluoroethylene barrier membranes and demineralized freeze-dried bone allografts as inductive/conductive materials. In this study the technique is applied in two partially exposed cylindrical hydroxyapatite-coated implants in extraction sites in one patient. Surgical reentry in both sites is presented, with histologic examination revealing new bone formation on the exposed root surface and the hydroxyapatite-coated implants.

Twenty-five subjects with a total of 50 subgingival restoratio ns participated in this study. At the beginning of the investigation, nine teeth that were considered hopeless because of the extent of their pathology were selected for extraction to evaluate histologically the restora tions and their effect on the adjacent tissues. The purpose of this article is to demonstrate the responses to the clinical applications as well as to the placement of resin-ionomers in subgingival lesions. Clinical and histologic evidence of epithlial and connective tissue adherence to resin-ionomer restorative materials was observed during the healing process.

Restoration of a periodontally compromised dental arch with a removable partial denture may require one or more design modifications. Multiple rests ensure that adequate vertical support remains in the event primary abutment teeth are lost. An open or closed base can be strategically placed in the maxillary major connector to facilitate the replacement of subsequently lost teeth. The location of finish lines can be modified to provide a smoother resin-to-metal transition when posterior teeth are lost. Wire direct retainers that provide more physiologically acceptable clasping of compromised teeth and that are easily adjusted and added to the prosthesis should be considered.