The influence of FDBA and autogenous bone particles on regeneration of calvaria defects in the rabbit: A pilot study

The histological behavior of bone formation using three biomaterials was examined including whether an 8 mm rabbit calvarial defect would behave as a critical size defect. Four trephine defects of 8 mm diameter in were created six rabbit parietal bones. A control defect was maintained only with coagulum and others were filled with autologous bone, FDBA (freeze dried bone allograft) and a mixture of autologous bone with FDBA, respectively. The animals were sacrificed after between 15 and 90 days at intervals of two weeks and the extracted samples were processed for histological evaluation. All control defects showed incomplete bone formation during 90 days of observation. The defects filled with FDBA and mixture of FDBA-autologous bone exhibited a higher regeneration degree than autologous bone after 60 days; however, the only biomaterial revealing complete mineralization of the original defect at 90 days was FDBA. In conclusion, 8 mm defects can be considered as critical size defects and only FDBA showed mature lamellar bone at 90 days.