In vitro and in vivo assessment of bone-implant interface: a comparative study

The present in vitro and in vivo comparison of three bioactive (HA, AP40, R KKP) and three bioinert (Ti6-Al4-V, Al2O3, ZrO2) materials was undertaken t o identify which of them provide(s) the most suitable coating for prosthese s implanted in patients with altered metabolic status. The experimental design included in vitro tests with human osteoblasts and morphological observations by scanning electron microscopy. For the in vivo evaluation, the materials were implanted in the femoral condyle of ovariec tomised and intact female rats, and two months after surgery an X-ray micro analytical study was performed. The in vitro study showed good biocompatibility with all materials. Microan alysis evidenced a similar behaviour with all materials except the two biol ogical glasses. The differences in Ga and P content observed between intact and ovariectomised rats can be explained by the intrinsic capability of bi ological glasses to undergo surface modifications in the presence of altera tions of the bone metabolism. Thus, their use seems to be indicated in reci pients with osteoporotic pathologies.