Purpose: To compare the efficacy of 2 common materials in sinus augmentation surgery and to assess their contribution when enriched with autogenous bone. Materials and Methods: The prospective human study was performed in 48 sinus grafting operations using b-tricalcium phosphate or deproteinized bovine bone (pure or mixed with 10% to 20% autogenous bone) or autogenous bone. Biopsy specimens were taken after 9 months. Statistical evaluation was done with a 2-sample t test (P .05). Results: When autogenous bone was used, 49.2% ± 3.1% of new bone was found, which is significantly higher than in all the other groups. A higher proportion (34.2% ± 13.1%) of the new vital bone was found in the deproteinized bovine bone group, in comparison with the b-tricalcium phosphate group (21.4% ± 8.1%) and the b-tricalcium phosphate composite graft group (24.0% ± 6.6%; P .05). No significant differences between single-component grafts and corresponding composite grafts were established. Conclusions: Sinus augmentation with the aforementioned augmentation materials is a well-accepted procedure. However, autogenous bone alone was the best material. More new bone was found using deproteinized bovine bone than b-tricalcium phosphate. The addition of 10% to 20% autogenous bone to the bone substitute did not significantly influence the new bone formation. Keywords: autogenous bone graft, b-tricalcium phosphate, composite graft, deproteinized bovine bone, histomorphometry, sinus augmentation