Surface spectroscopic characterization of titanium implant materials

Titanium is a relatively widely and successfully used biomaterial, especially in the dental and orthopaedic fields. The surface oxide which almost always covers titanium is considered to be an important factor for the favourable tissue response obtained with Ti implants. This paper describes the properties of surface oxides on Ti by discussing some selected examples of surface spectroscopy analyses of Ti surfaces prepared by different methods, including; clinical procedures (machining, solvent cleaning, sterilization), electrochemical methods (electropolishing and anodic oxidation), thermal oxidation in air, and nitrogen-ion implantation. The main analytical techniques are scanning AES and XPS (ESCA). Complementary information is obtained from secondary ion mass spectrometry (SIMS), Rutherford backscattering (RES), and nuclear reaction analysis (NRA). Selected spectroscopic results are discussed with reference to microstructural studies published elsewhere. Comparison between pure Ti and Ti6Al4V alloy shows many similarities, but also some significant differences between the two materials. The paper also comments briefly on surface contamination and cleaning, and discusses some selected examples of biological studies on different titanium surfaces.