Sinus floor augmentation using large (1-2 mm) or small (0.25-1 mm) bovine bone mineral particles: a prospective, intra-individual controlled clinical, micro-computerized tomography and histomorphometric study.

OBJECTIVES: To compare the amount of newly formed bone after sinus floor augmentation with two different particle sizes of bovine bone mineral (BBM) using clinical, micro-computerized tomography (CT) and histological techniques. METHODS: Bilateral sinus floor augmentations were performed in 10 patients. Six to 9 months later, bone samples were retrieved and analyzed. RESULTS: Results: Both groups were not different in vertical bone height achieved after augmentation, post-operative complications and maximal torque for the insertion of implants. Micro-CT measurements could not detect a statistically significant difference in bone volume between the groups (with a tendency for new more bone in the small granules group). Histomorphometric analysis revealed that both granule sizes produced the same pattern of bone formation, surrounding the graft granules, and producing a shape of a network, "bridging" between the BBM particles. Multi-nucleated giant cells, probably osteoclasts, were observed directly on the BBM particle surface in both groups. The osteoclast-like cells preferred the small-size BBM particles and not the large particles both in the small-size and the large-size granules group. CONCLUSION: Both sizes of BBM granules preformed equally and achieved the aim of the sinus floor augmentation procedure clinically and histologically.