Corrosion resistance of Ni-Ti, Thermoactive alloy, and SS 316 L alloy in artificial saliva (AS) in the absence and presence of coffee has been evaluated by electrochemical studies such as polarization study and AC impedance spectroscopy. The polarization and AC impedance spectroscopy studies lead to the conclusion that corrosion resistance of the alloys decreases in the following order: SS 316 L alloy > Thermoactive alloy> Ni-Ti alloy. In all the three cases, the corrosion resistance of the wires increases in the presence of coffee. Among the three orthodontic wires, SS316L alloy is the best candidate.
Key words: artificial saliva; corrosion; metals; coffee; polarization study; AC impedance spectra.
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