Corrosion Resistance and In-vitro Osteoblast Response of Calcium-phosphate Coated Titanium Substrates Prepared by Laser Sintering

A rough surface texture was found on laser sintered titanium substrate, which was responsible for instability of the calcium phosphate layer from the point of view of obtaining good adhesivity to the substrate at given preparation conditions. After the mechanical treatment and following soaking of Ti substrate in 3 M NaOH solution, the surface texture was much smoother than in the original sample and a fiber-like titanate layer was created on the surface. This treatment improved the mutual bonding between titanium and the electrophoretically deposited calcium phosphate coating. The final coating contained two major phases – rutile and β−tricalcium phosphate. The deposition of calcium phosphate on Ti substrate significantly enhanced its corrosion resistance. Results of invitro testing confirmed a low cytotoxicity of both the NaOH treated and calcium phosphate coated Ti substrates. The calcium phosphate layer increased the in-vitro ALP activity of osteoblasts.