Calcium phosphate formation within sol-gel prepared titania in vitro and in vivo.

Calcium phosphate formation is induced within sol-gel prepared titania and grows toward a calcium phosphate solution in which the titania is immersed. The implantation of this sol-gel prepared titania film coating on TiA16V4 core into the femurs of goats shows an accumulation of calcium phosphate within the titania film 12 weeks postoperatively, which leads to the connection of the titania film coating to the bone. Therefore, sol-gel prepared titania is probably bioactive. The results indicate that hydrated titania gel is able to generate calcium phosphate by intake of calcium and phosphate from the surrounding solution. Sufficient TiOH concentration at the titania surface is needed to start this process. Titanium could be bioactive, if its hydrolysis can be accelerated.