<![CDATA[Metallic materials for orthodontic applications must exhibit good corrosion resistance, as they operate within the corrosive environment of the oral cavity. Titanium and its alloys are widely used as biomaterials owing to their favorable biocompatibility and corrosion resistance. This study aimed to evaluate the corrosion behavior of Ti-12Cr alloy under three heat-treatment conditions, namely solution treated (ST), aged for 30 ks (AT 30 ks), and aged for 60 ks (AT 60 ks), and to compare it with commercially pure titanium (CpTi) in AFNOR artificial saliva at 37°C. Corrosion testing was performed using the weight-loss method with immersion periods of 1, 2, and 3 weeks, using one specimen for each condition. Surface characterization was conducted using Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray Spectroscopy (EDX), while the mechanical properties were evaluated through Vickers hardness testing before and after immersion. The results showed that all materials experienced weight loss during immersion. Ti-12Cr AT 60 ks exhibited the lowest average corrosion rate at 3.88 × 10⁻⁶ mmpy, followed by Ti-12Cr AT 30 ks at 4.18 × 10⁻⁶ mmpy and Ti-12Cr ST at 5.00 × 10⁻⁶ mmpy, whereas CpTi showed the highest corrosion rate at 7.70 × 10⁻⁶ mmpy. Hardness testing revealed a decline in hardness values for all materials during immersion, with Ti-12Cr AT 30 ks maintaining the highest hardness throughout the observation period. The findings indicate that Ti-12Cr possesses better corrosion resistance than CpTi, and that increasing the aging time from 30 ks to 60 ks resulted in a further reduction in the average corrosion rate. The Ti-12Cr AT 60 ks condition yielded the highest corrosion resistance, whereas Ti-12Cr AT 30 ks retained the highest hardness after immersion. These results reveal a divergence between the corrosion resistance and hardness responses to heat treatment. Overall, Ti-12Cr demonstrates potential as a nickel-free.]]>
