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. Schlagwörter: allografts, dental implants, maxillary sinus elevation, xenografts