Hydrothermal Synthesis of Bioactive Titanium Oxide-CaCO3 Films with Aqueous Ca(OH)2/KHCO3 on Pure Ti

Porous titanium is an excellent biomaterial candidate because of its ability to maintain appropriate strength once it is implanted. The osteointegration of titanium and its alloys is less than that of bioactive ceramics. Therefore, various surface modification techniques have been developed to improve the osteointegration. We successfully prepared titanium dioxide (TiO2) and calcium titanate (CaTiO3) films on the surfaces of pure Ti by combined chemical-hydrothermal treatment. Especially in CaTiO3, the formation of apatite was promoted due to the release of Ca 2+ from the surface of CaTiO3 in Hanks’ solution. Calcite (CaCO3) is a biodegradable material that must enhance hydroxyapatite (HAp) formation in simulated body fluid as well as in CaTiO3. The purpose of the present study was to synthesize bioactive films including CaCO3 on pure Ti substrates and porous titanium by chemical-hydrothermal treatment using Ca(OH)2 and KHCO3. The modified porous materials were tested mechanically in a compression test. CaTiO3-CaCO3 and TiO2-CaCO3 films were synthesized by choosing an ion concentration ratio of CO3 /Ca in the aqueous solution for hydrothermal treatment. CaTiO3-CaCO3 films were also synthesized on porous titanium by hydrothermal treatment. Compressive properties of porous titanium after the treatment were similar to those prior to the treatment. The films produced by the present surface modification showed no significant changes compared to the original properties.