Deposition of substituted apatites onto titanium surfaces using a novel blasting process

A novel coating technique has been developed to modify the surface of metallic substrates. By simultaneously blasting the surface with an abrasive and a dopant, it is possible to impregnate the dopant into the surface. In this study, the surface of a titanium alloy has been impregnated with either hydroxyapatite or a variety of substituted (magnesium, carbonate or fluoro) apatites. EDX and XPS analysis clearly reveal high levels of dopant inclusion in the surface to a depth of less than 10 μm. A combination of XRD and ion elution measurements suggest that highly crystalline precursors are not degraded by the process and dissolution of materials with low crystallinity proceeds at a significantly higher rate than that of the crystalline hydroxyapatite. The biocompatibility of these surfaces has been investigated using an in vitro osteoblast proliferation study and the carbonate doped material was found to induce the highest level of cell proliferation.