O interstitial energetics in Ti from ab initio calculations

Ti-porcelain systems have been used in prosthetic dentistry since 1980. The chemical bonding in this kind of systems is generally attributed to oxidic compounds. The porcelain functions as an O donator and stoichiometric and non-stoichiometric titanium oxides are formed at the interface. These oxides result in substantial distortion of the crystalline structure and failure of bonding. A useful technique for surface conditioning is the silicon-ion implantation, which results in the formation of a metal-silicon zone protecting against O diffusion. In dental materials technology, processes on the atomic scale have been investigated insufficiently or not at all. In this work, we present ab initio calculations on the energetics of an O interstitial in a Ti crystal. The aim of our study is getting new insight into the atomic scale properties of these Ti-porcelain systems.