In vitro and in vivo bioactivity of a titanium/hydroxyapatite composite

A microcomposite of titanium/hydroxyapatite (Ti/HA) was successfully fabricated by powder metallurgy technique. In vitro and in vivo bioactivity of the composite was investigated in the present work. When the composite is immersed in the simulated body fluid for a certain time, a poor-crystallized, calcium-deficient, carbonate-containing apatite film forms on the surface of the composite. In addition, the apatite is also incorporated with a little magnesium and chlorine element. The time required to induce apatite nucleation is less than two hours. After 1-month implantation in rabbit femur, the bone formation is very active and plenty of new bone is observed at the composite-bone interface. With the increase of implantation time, the amount of new bone increases. After 6-month implantation, the gap between the composite and host bone has been completely filled with mature bone, and there is no difference between new bone and host bone. In conclusion, the Ti/HA composite has excellent both in vitro and in vivo bioactivity.