Bioactive Modification of Titanium by Coating Bioactive Glasses

Two different bioactive glasses, 55SF (55.1SiO2-3.4P2O5-9.2Na2O-27.8CaO-4.5CaF2; mol.%) and 50SB (50.1SiO2-3.4P2O5-9.2Na2O-32.3CaO-5B2O3; mol.%), were used to coat titanium metal in order to make it bioactive. The bonding characteristics between titanium substrate and bioactive glass were examined and then the hydroxyapatite formation on the coated specimen was studied after its reaction in a simulated body fluid (SBF). A thin film X-ray diffractometer and scanning electron microscope were employed for the examination of the coated layer surface. Ionic concentrations in the reacted solution were also measured. When the 55SF glass was coated with a ground coat, a Ti5Si3 crystal was formed at the interface between the titanium and the glass coat. There was no hydroxyapatite found on this layer when reacted in a SBF. 50SB glass was used as a cover coat and fired at various temperatures. An amorphous phase was observed when fired at 800℃, while oxyapatite crystal was obtained when fired at 900℃. When those samples were reacted in a SBF, hydroxyapatite crystal was deposited only on the sample that had an amorphous phase.