Objectives: The aim of the present study was to evaluate the effect of anorganic bone particles of two different sizes (300-500 and 850-1,000μm) on new bone formation in a guided bone regeneration model system.
Methods: A total of 12 rabbits underwent grafting using particles of different sizes, and followed with histologic and histomorphometric analysis.
Results: Histologically, in both the small- and large- particle groups, newly formed bone was seen adjacent to the original skull surface and showed outgrowths to the center of the secluded graft space 4 weeks after implantation. Some particles near the skull surface were bonded to the newly formed bone and osteoconductive bone growth was seen along their surface. Ten weeks after implantation, the created area grafting with the small particles appeared to contain a denser bone structure than with the large particles. Histomorphometric analysis revealed a higher density of newly formed bone in the small-particle group than in the large-particle group both 4 and 10 weeks after implantation. The total newly formed bone-particle contact area and the bone volume ratio in the interparticular spaces were also significantly higher in the small-particle group both 4 and 10 weeks after implantation.
Conclusion: We conclude that graft bone particle size and interparticular space are important determinants of osteogenesis during guided bone regeneration.
Acknowlegement: The study was supported by Beijing scientific and technological new star program (2006B62) and the Scientific Research Foundation for the Returned Overseas Chinese Scholars, State Education Ministry.