Sinus elevation with alloplasts or xenogenic materials and implants: an up-to-4-year clinical and radiologic follow-up.

PURPOSE: The clinical and radiologic results of bone substitute application in the sinus elevation procedure were evaluated for up to 4 years after a grafting procedure followed by implant placement. MATERIALS AND METHODS: Between 1997 and 2001, augmentation of the maxillary sinus floor with alloplastic or xenogenic materials was performed in 34 nonsmoking patients with generally good health. However, only 18 patients attended all of the required annual clinical and radiographic examinations and thus were included in the study. Mean follow-up after implantation was 29 months. RESULTS: At the second-stage surgery all the implants were osseointegrated, except for 1 Frialit-2, which was removed. Following prosthetic rehabilitation no implant was lost after 4 years of function, for a prosthetic success rate of 100%. The cumulative implant survival rate after 48 months was 97% (36 of 37 implants). DISCUSSION: Osseointegrated implants are a reliable treatment option for restoring the posterior maxilla, and final predictability was not influenced by their placement in augmented areas after sinus elevation with bone substitutes. CONCLUSIONS: The survival rate obtained with this study is similar to that expected for implants placed in nongrafted areas. This study showed that alloplasts and xenogenic materials are reliable for bone regeneration in the subantral cavities, as they showed very low resorption in the present study.

Bone resorption around dental implants placed in grafted sinuses: clinical and radiologic follow-up after up to 4 years.

PURPOSE: The long-term results of endosseous implants depend on the maintenance of bone support. The aim of this study was to evaluate radiologically bone resorption around dental implants placed in grafted sinuses after up to 4 years of function. MATERIALS AND METHODS: Between 1997 and 2001, augmentation of the maxillary sinus floor with alloplastic (Biostite) or xenogenic (Bio-Oss) materials was performed in 34 patients. RESULTS: Eighteen patients participated in the study. Twenty-six sinus augmentations were performed on these 18 patients, and they received 37 implants. The change in marginal bone level around the implants at the mesial side was 1 mm during the first year after the abutment connection, followed by an annual loss of 0.1 mm. The change in marginal bone level around the implants at the distal side was 1.1 mm during the first year after the abutment connection followed by an annual loss of 0.2 mm. DISCUSSION: The implant survival rate observed in this study is in line with data previously reported for patients treated with implants in the posterior maxilla without bone atrophy. The results for implants placed into sinuses grafted with Bio-Oss were similar to the results for implants placed in sinuses grafted with Biostite. CONCLUSION: Although this study involved a limited number of procedures, it confirmed that alloplastic and xenogenic materials can be reliable for bone regeneration in subantral cavities. The angular defects present both at the distal and mesial sides of the implants were comparable to those observed at implants placed in native bone.