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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.

A series of titanium-silver-iron ternary alloys have been prepared in this study, and their feasibility as dental materials has been evaluated by the microstructural examination, mechanical testing, corrosion resistance evaluation, surface analysis, and cytotoxicity tests. More and more b-Ti phase appears at room temperature and retains with the increasing of Fe content in Ti-5Ag-xFe alloy systems. The compression strength, wear resistance, and microhardness increase largely (p < 0.05) by the addition of element Fe to Ti-Ag alloy. Moreover, when comparing with commercial pure titanium (CP Ti), nobler electrochemical corrosion behavior could be obtained for Ti-5Ag-1Fe and Ti-5Ag-2.5Fe alloys in the 1% lactic acid solution (pH ¼ 2.1) and 0.1 mol/L H 2 O 2 þ 0.9% NaCl solution (pH ¼ 4.0). The released metal ions from Ti-5Ag-xFe alloys into the simulated fluid are trace, similar to the case of CP Ti. The addition of Fe slightly decreases the corrosion resistance of Ti-5Ag alloy. All experimental Ti-5Ag-xFe alloy extracts do not present any cytotoxicity to L-929 and NIH3T3 cell lines. All in all, the combination of superior corrosion resistance and enhanced mechanical properties make Ti-5Ag-1Fe alloy and Ti-5Ag-2.5Fe alloy suitable for dental applications.