Osteoconductive TiO2 Coating on Titanium Using Anodizing in High Content Phosphoric Acid
In this study, anodizing of Ti in the various concentration of H3PO4 aqueous solutions gave TiO2 films, and the osteoconductivity was examined using in vivo testing. In the anodizing treatment, anodizing potential of < 200 V was applied to the Ti substrate in H3PO4 aqueous solutions with the concentration of 0.1 to 14 M at 298 K. The coatings were evaluated using SEM, XRD, FT-IR and XPS. In in vivo testing, the coated samples were implanted in the rats’ tibia for 14 d to evaluate the osteoconductivity. In H3PO4 aqueous solutions with any concentration, anatase-type TiO2 films were obtained on the Ti substrate by anodizing. The crystallinity of anodized TiO2 films depended on the concentration of H3PO4 and sparking. In less than 2 M H3PO4, anatase with high crystallinity was formed. On the other hand, anodizing with sparking in more than 4 M H3PO4, gave low crystallinity anatase film. In in vivo testing, osteoconductivity of the coatings with low crystallinity anatase was much higher than that with high crystallinity.