Susceptibility to corrosion of laser welding composite arch wire in artificial saliva of salivary amylase and pancreatic amylase

In this study, laser-welded composite arch wire (CAW) with a copper interlayer was exposed to artificial saliva containing salivary amylase or pancreatic amylase, and the resultant corrosion behavior was studied. The purpose was to determine the mechanisms by which salivary amylase and pancreatic amylase contribute to corrosion. The effects of amylase on the electrochemical resistance of CAW were tested by potentiodynamic polarization measurements. The dissolved corrosion products were determined by ICP-OES, and the surfaces were analyzed by SEM, AFM and EDS. The results showed that both exposure to salivary amylase and pancreatic amylase significantly improved the corrosion resistance of CAW. Even isozyme could have different influences on the alloy surface. When performing in vitro research of materials to be used in oral cavity, the effect of α-amylase should be taken into account since a simple saline solution does not entirely simulate the physiological situation.