Effect of different post-treatments on the bioactivity of alkali-treated Ti–5Si alloy

摘要

BACKGROUND:As titanium (Ti) alloys are bioinert, various chemically-modified Ti surface has been developed to promote bioactivity and bone ingrowth. OBJECTIVE:In this study, various post treatments (water aging, hydrothermal, and heat treatments) were applied to NaOH-treated Ti–5Si to improve its bioactivity. METHODS:The bioactivity of surface-modified Ti–5Si was access by using the apatite formation ability of Ti–5Si surfaces soaking in a simulated body fluid (SBF). RESULTS:The results showed that the NaOH-treated surface formed a porous network structure composed of sodium titanate hydrogel, which was changed to sodium titanate after subsequent post treatments, whereas sodium titanate, anatase and rutile phases were found on the Ti–5Si surfaces after heat treatment. After immersion in SBF for 14 days, compact apatite layers were observed on the surfaces of all the Ti–5Si tested. The results of XRD and FTIR indicated that the apatite deposited on the Ti–5Si substrate with various surface modified conditions was carbonate-substituted hydroxyapatite. CONCLUSIONS:The apatite-forming ability of the surface of the Ti–5Si was excellent, even though Ti–5Si was not subjected to surface modifications. As a result, the bioactivity of Ti–5Si alloy was verified by the apatite-forming ability, making it suitable for use in orthopedic and dental implants.