OBJECTIVEto evaluate the corrosion resistance of a new titanium alloy for dental restoration in artificial saliva.

METHODSin simulated oral environment, the electrochemical behavior of a new titanium alloy (Ti-12.5Zr-3Nb-2.5Sn) for dental restoration based on the d-electron alloy design method with high elastic modulus, high mechanical and good biological safety properties was investigated together with that of Ti-6Al-4V and TA2 as control groups. The anodic polarization curve and polarization resistance of these alloys were analyzed and the element release of Ti-12.5Zr-3Nb-2.5Sn and Ti-6Al-4V alloy after immersion in artificial saliva for 1, 2, 3, 5, 7, 15 d were measured.

RESULTSpolarization curve indicated that Ti-6Al-4V alloy had lower breakdown potential (0.8 V) than Ti-12.5Zr-3Nb-2.5Sn alloy did (> 2.5 V). Ti-6Al-4V alloy showed higher passivation current density (1.45 × 10(-4) - 1.09 × 10(-3) A/cm(2)) than Ti-12.5Zr-3Nb-2.5Sn alloy (3.32 × 10(-6) - 3.46 × 10(-5) A/cm(2)) and TA2(5.03 × 10(-6) - 2.65 × 10(-5) A/cm(2)) did. Polarization resistance results showed that polarization resistance volume of TA2, Ti-12.5Zr-3Nb-2.5Sn alloy and Ti-6Al-4V alloy were 371.0, 252.0, and 60.1 kΩ×cm(2) respectively. With the increasing of dipping time in artificial saliva, the ion release of Ti-12.5Zr-3Nb-2.5Sn alloy and Ti-6Al-4V alloy increased to different degrees. Ti-6Al-4V alloy always showed more ion release than Ti-12.5Zr-3Nb-2.5Sn alloy did in the experiment.

CONCLUSIONSdata from this study indicated that Ti-12.5Zr-3Nb-2.5Sn alloy, as a dental restoration material, had good corrosion resistance in artificial saliva.