Short Implants Placed with or without Grafting in Atrophic Sinuses: The 3-Year Results of a Prospective Randomized Controlled Study.

BACKGROUND: The question whether a minimal maxillary residual bone height (RBH) allows the predictable use of osteotome sinus floor elevation (OSFE) remains unresolved. PURPOSE: To evaluate the efficacy of short implants placed with OSFE in an RBH of </=4 mm and to compare bone levels around implants placed with (control) or without (test) grafting after 3 years. MATERIALS AND METHODS: Eight-millimeter implants were placed by OSFE in sinuses randomized to receive anorganic bovine bone or no grafting material. Healing time before prosthetic rehabilitation was 10 weeks. Peri-implant bone levels were measured on standardized periapical radiographs. RESULTS: Thirty-seven implants (17 test, 20 control) were placed at a mean RBH of 2.4 +/- 0.9 mm. Three implants failed during the 3-year follow-up. After 3 years, all implants had gained endosinus bone (test: 4.1 +/- 1.0 mm; control: 5.1 +/- 1.2 mm; p = .001). Mean bone gain was stable between 1 and 3 years in both groups. CONCLUSIONS: Grafting is unnecessary to achieve bone augmentation of 4.1 mm; however, more bone is gained with grafting. Bone gained over 1 year was retained. Atrophic posterior maxillae can be predictably rehabilitated using OSFE and simultaneous placement of 8-mm implants.