Corrosion behavior of surface-modified titanium in a simulated body fluid

We investigate the influence of micro-sandblasting and electrochemical passivation on properties such as corrosion rate and surface roughness, which are important to the biocompatibility of titanium (Ti), using surface analysis techniques and electrochemical measurements. Results of microscopy and surface profilometry experiments reveal roughened but uniform surface topography with an average surface roughness in the 0.87-1.06 mu m range, depending on the alternating current passivation voltage applied to the micro-sandblasted samples. Open circuit potential versus time measurements in Hank's Balanced Salt Solution (HBSS, a simulated body fluid) allow determination of the corrosion potential (E (corr)) and reveal a shift of E (corr) toward higher values upon passivation, thus pointing to increased corrosion stability. Corrosion rates in HBSS range between 0.049 and 0.288 mu m year(-1) for micro-sandblasted and passivated Ti, as compared to that for the micro-sandblasted and non-passivated surface that is 0.785 mu m year(-1). Results from this study demonstrate that micro-sandblasting coupled with electrochemical passivation provides a roughened surface with increased corrosion stability and a low corrosion rate in HBSS. Application of this technique to Ti in medical and dental applications may be expected to result in an improvement of biocompatibility.