Preparation of magnesium containing bioactive TiO₂ ceramic layer on titanium by hydrothermal treatment

Surface modification on titanium was carried out in order to improve its bioactivity. Pure titanium was hydrothermally treated in 0.1 mol/L MgCl ₂ solutions with different pH at 200°C for 24hr. Surface morphology, roughness, wettability and chemical composition were characterized before and after treatment. Simulated body fluid (SBF) was employed to examine in vitro bioactivity. After hydrothermal treatment, nano-sized precipitations were observed and these surfaces showed superhydrophilicity. Ti-O-Mg chemical bonding was formed on titanium surface after hydrothermal treatment, however, under high pH, Mg(OH)₂ was precipitated from the solution. Hydrothermal treatment increased thickness of the oxide layer and the oxide layer was modified with magnesium (Mg). Apatite spheres were precipitated on hydrothermally treated samples after immersion in SBF for 2 days. However, the precipitation of apatite was depressed with increasing Mg concentration. The hydrothermal treatment was expected to be an effective method to fabricate titanium implant with good bioactivity.