Apatite-forming ability of thermally treated titania with various phase compositions

• Heat treatment process of titania ceramics on in vitro bioactivity was evaluated.
• Phase composition has minor influence on apatite-forming ability.
• The essential factor for deposition of apatite is grain size.

Titania ceramics with various anatase-rutile phase ratios, grain size and surface area were prepared by thermally treating pressed compacts at different temperature regimes. The effect of heat treatment process on in vitro apatite-forming ability was evaluated by immersion in a simulated body fluid. Results demonstrate that bonelike apatite formation on titania ceramics is affected by multiple factors including grain size, specific surface area and phase composition. The results indicate that the phase composition has minor influence on apatite-forming ability of titania ceramics comparing to grain size and specific surface area. The essential factor for deposition of apatite is grain size.