Corrosion Behavior and In Vitro Cytotoxicity of Ni–Ti and Stainless Steel Arch Wires Exposed to Lysozyme, Ovalbumin, and Bovine Serum Albumin

[Image: see text] In this study, the tendency and mechanisms by which protein and mechanical loads contribute to corrosion were determined by exposing Ni–Ti and stainless steel arch wires under varying mechanical loads to artificial saliva containing different types of protein (lysozyme, ovalbumin, and bovine serum albumin). The corrosion behavior and in vitro cytotoxicity results show that exposure to both protein and mechanical stress significantly decreased the corrosion resistance of stainless steel and increased the release of toxic corrosion products. Adding protein inhibited the corrosion of Ni–Ti, but the mechanical loads counteracted this effect. Even proteins containing the same types of amino acids had different effects on the corrosion resistance of the same alloy. The effect of protein or stress, or their combination, should be considered in the application of metal medical materials.