Titanium scaffolds for osteointegration: mechanical, in vitro and corrosion behaviour

While titanium has been successful as an orthopaedic or dental implant material, performance problems still persist concerning implant-bone interfacial strength and mechanical modulus mismatch between metal and tissue. Porous structures are an advantageous alternative because the elastic modulus can be adjusted to match that of bone, thereby preventing bone resorption. Furthermore, to achieve early and strong stabilization theses structures may be coated with bioactive deposits, as hydroxyapatite. In the present work, titanium porous scaffolds were produced from TiH2 slurry by a replication sponge reactive sintering method, and coated with hydroxyapatite by the sol-gel process. The obtained structures were microstructurally and mechanically characterized. Their in vitro bioactivity was investigated by soaking in a simulated body fluid (SBF). Electrochemical characterization was also performed in order to evaluate the effect of coating on corrosion resistance. The scaffolds exhibit a three-dimensionally interconnected porous structure that can be mechanically and morphologically compared to trabecular bone. Their in vitro bioactivity suggests potential for osseous integration. Coating also improves corrosion resistance in physiologically saline environment.