Grafting of deproteinized bone particles inhibits bone resorption after maxillary sinus floor elevation

Objectives: To evaluate the value of deproteinized bone particles on bone resorption in the augmented space after maxillary sinus floor elevation in rabbits. Material and methods: A total of 20 rabbits underwent bilateral grafting, using blood clots (control group) and deproteinized bone particles (experimental group), and followed with histologic and histomorphometric analysis. Results: Two weeks after grafting, the augmented space was almost completely obliterated by both newly formed bone and fibrous connective tissue in the control group. Some osteoclasts were found on the surface of newly formed bone, especially near the elevated sinus membrane. In the experimental group, newly formed bone was found along the elevated sinus membrane, the cortical wall of the augmented space, and the surface of deproteinized bone particles near the cortical wall. Some osteoclasts were found along the deproteinized bone particles and a few adhered to the surface of the newly formed bone. Eight to 10 weeks after implantation in the control group, most of the newly formed bone had been resorbed. In the experimental group, newly formed bone was found in most parts of the convex augmented space. Histomorphometrical analysis showed that the augmented height was significantly higher in the experimental group than in the control group at all evaluation times. Bone area was significantly higher in the experimental group than in the control group at 6, 8, and 10 weeks after implantation. The area of grafted deproteinized bone particles did not change significantly from 2 to 10 weeks. Conclusion: Slowly resorbed deproteinized bone particles contribute to stable augmentation of the maxillary sinus floor by inhibiting bone resorption.