Autogenous bone with or without hydroxyapatite bone substitute augmentation in rat calvarium within a plastic cap.

We evaluated the effect of autogenous bone (AB) and hydroxyapatite bone (HA) for the assessment of bone augmentation beyond the skeletal envelope in the rat calvarium. The calvaria of 12 rats were exposed and 2 plastic caps were placed with AB and HA or AB alone in the calvarium. Images of bone augmentation within the plastic caps were taken using micro-CT (R_mCT). Histologic sections were cut along the same plane as those used for the R_mCT images at 12 weeks. Bone volume (BV) was calculated using BV-measuring software. BV increased at both the experimental and control sites. The newly generated tissue did not significantly differ between the experimental and control sites; however, the mineralized tissue was significantly higher at control sites compared with experimental sites. The results indicate that the combination of HA and AB was biocompatible and allowed osteoconduction.