Bioactive Composite Coating on Titanium Implants for Hard Tissue Repair

A bioactive composite coating consisting of one layer of titania and one layer of apatite was formed on Ti substrate. The first layer of crystalline titania was deposited on Ti at low temperatures either through oxidation of Ti by hydrogen peroxide solution or through hydrolysis of TiF4 or TiCl4 solution. It was shown that the crystalline titania, either in the form of anatase or rutile, induced formation of the second layer of apatite in a simulated body fluid. However, the trace elements in the titania layer affected greatly apatite formation. The Cl incorporated in the titania layer did not hinder apatite formation while F did. The two-layer composite coating should enhance bonding of Ti implants to bone tissue.