In vitro calcification of orthopaedic implant materials

The formation of an apatite-like layer is achieved by immersing Ti6Al4V and TiAl2.5Fe substrata in Hank's Balanced Salt Solution (HBSS). The layer was characterized by several techniques, namely X-ray microanalysis, X-ray diffraction and X-ray photoelectron spectroscopy. The results suggest that the layer produced by immersion in HBSS is in the form of an amorphous apatite. The pH and the concentrations of calcium and phosphate were monitored as a function of time. in vitro tests with rat bone marrow were performed in order to mimic the bone/biomaterial interface. They were performed on both immersed and non-immersed samples. The in vitro bone marrow results suggest that the apatite-like layer formed may improve the bone bonding characteristics of the studied titanium alloys.