Bioactivity of porous titanium with hydrogen peroxide solution with or without tantalum chloride treatment at a low temperature.

In this study, porous titanium was treated by a hydrogen peroxide solution with (HT) or without (HO) tantalum chloride at a low temperature to endow its bioactivity. The microstructure, film stability and in vitro and in vivo bioactivity of HT-treated and HO-treated porous titanium were investigated, and the non-treated one was used as control. After HT treatment, a well-crystallized titania nanoparticle film consisting of anatase phase with good film stability was formed on the surface of porous titanium, and the tantalum element appeared in the film, while the HO-treated porous titanium surface showed a dual structure with well-aligned nanorods as an outer layer and condensed nanoparticles as an inner layer consisting of a mixture of well-crystallized anatase and rutile phases. In vitro bioactivity assessment showed that both HT- and HO-treated porous titanium possessed high apatite-forming ability. More importantly, after implantation in the dorsal muscles of dogs, the HT- and HO-treated implants induced ectopic bone formation in its inner pores after 5 months, while the non-treated one did not. The present study showed that HT-treated porous titanium possessed good film stability and bioactivity to be used as bone repair materials in clinic under load-bearing conditions.