Effect of treatment temperature on the biocompatibility and mechanical strength of hydroxyapatite coating formed on titanium using calcium phosphate slurry

Calcium-phosphate-slurry processing is a useful technique for fabricating bioactive layers on titanium substrates. This process involves burying a Ti substrate in calcium phosphate slurry, followed by heating the slurry containing the Ti substrate in air. In the present study, we determined the optimum heating temperature for this process. The mechanical strength of the layer was reduced owing to an increase in the layer thickness at increased heating temperatures. The highest strength was obtained with a heating temperature of 898 K. Though varying the heating temperature changed the surface roughness, no difference in cytotoxicity was observed among the substrates. On the other hand, increasing the heating temperature improved the precipitation of calcium phosphate onto the treated substrates, showing promise for their extensive osteogenesis. A heating temperature of 898 K was determined to be optimal for fabricating bioactive titanium with good biocompatibility and excellent mechanical strength.