Osteoconduction of different sizes of anorganic bone particles in a model of guided bone regeneration

The aim of this study was to evaluate the effect of two different sizes of anorganic bone particles (300-500 and 850-1000 μm) on the formation of new bone in a model of guided bone regeneration. In both groups, newly formed bone was seen histologically adjacent to the original surface of the skull, and there were outgrowths to the centre of the secluded graft 4 weeks after implantation. Some particles near the surface were in contact with the newly formed bone, and osteoconductive bone growth was present along their surface. Ten weeks after implantation the area created by grafting with small particles seemed to have a denser structure than that created with large particles. Histomorphometric analysis showed 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 contact length between newly formed bone and particles and the ratio of bone:space between the particles were also significantly higher in the small-particle group at both time points. We conclude that the size of grafted particles of bone and the spaces between particles are important determinants of osteogenesis during guided bone regeneration.