Surface Characterization and Cell Response of Binary Ti-Ag Alloys with CP Ti as Material Control

In this study, the surface passive films, dissolution behavior and biocompatibility of Ti-Ag alloys (with 5%, 10% and 20% Ag) were evaluated by X-ray diffraction (XRD) tests, electrochemical corrosion tests, X-ray photoelectron spectroscopy (XPS) tests, dissolution tests and in-vitro cytotoxicity tests. The surface films on the Ti-20Ag alloy are rich in Ti and much deficient in Ag with respect to alloy composition, as identified by XPS. Compared to CP Ti, Ti-5Ag and Ti-20Ag alloys show larger impedances and lower capacitances, which can be associated with an increase of the passive layer thickness. Moreover, all Ti-Ag alloys exhibit negligible or low metal release in the test solutions. The in-vitro cytotoxicity results show Ti-Ag alloys seem to be as cytocompatible as CP Ti. From the viewpoint of surface passive film and cytotoxicity, Ti-5Ag and Ti-20Ag are considered to be more suitable for dental applications.