Corrosion of laser-welded NiTi shape memory alloy and stainless steel composite wires with a copper interlayer upon exposure to fluoride and mechanical stress

Abstract

In this study, laser-welded composite arch wire (CAW) with a copper interlayer was exposed to artificial saliva containing different concentrations of fluoride and to varying mechanical loads, and the resultant corrosion behavior was studied. The purpose was to determine the mechanisms by which fluoride and mechanical loads contribute to corrosion. Both exposure to fluoride and mechanical stress significantly decreased the corrosion resistance of CAW. Increasing concentrations of fluoride and loading stress caused increases of copper released and weight lost from CAW. Although the corrosion resistance of CAW declined with increasing fluoride concentration, it still meets the stability requirements for clinical use.