This study characterized the electrochemical behavior of Ti-Hf binary alloys in a simulated oral environment. Ti-Hf alloys (10, 20, 25, 30, 35 and 40 mass% Hf) were prepared by arc-melting titanium sponge and hafnium sponge. Specimens of each alloy (n = 4) were prepared using a dental titanium casting system with a MgO-based investment. Specimens were inspected with X-ray radiography to ensure minimal internal porosity. Castings (n = 4) made from pure titanium and commercially pure titanium were used as controls. The ground flat surface (10 mm • 10 mm) on each specimen where approximately 30 lm was removed was used for the characterization. Sixteen-hour open-circuit potential (OCP) measurement, linear polarization and potentiodynamic cathodic polarization were performed sequentially in aerated (air + 10% CO 2 ) MTZ synthetic saliva at 37 °C. Potentiodynamic anodic polarization was conducted in the same medium but deaerated (N 2 + 10% CO 2 ) 2 h before and during testing. Polarization resistance (R P ) and Tafel slopes were determined, as were corrosion current density (I CORR ) and passive current density (I PASS ). Results were subjected to nonparametric statistical analysis (a = 0.05). The OCP stabilized (mean values À229 mV to À470 mV vs. SCE) for all specimens after the 16-h immersion. Similar passivation was observed for all the metals on their anodic polarization diagrams. The Kruskal-Wallis test showed significant differences in OCP among the test groups (p = 0.006). No significant differences were found in R P , I CORR or I PASS among all the metals (p > 0.3). Results indicate that the electrochemical behavior of the Ti-Hf alloys examined resembles that of pure titanium.