Degradation of 316L stainless steel sternal wire by steam sterilization

Sterilization is an important step prior to the implantation of medical devices inside the human body. In this work we studied the influence of steam sterilization cycles on the oxide film properties of stainless steel sternal wire. Characterization techniques such as open-circuit potential, potentiodynamic measurement, electrochemical impedance spectroscopy, cathodic stripping, transmission electron microscopy, atomic force microscopy and scanning electron microscopy were employed to investigate the cycles of steam sterilization on the corrosion behavior of sternal wire. The results showed that the oxide properties are a function of the number of steam sterilization cycles and deteriorate as the number of cycles increases. Steam sterilization might damage the implant integrity and heavy metals could be released to the surrounding tissues due to deterioration of the oxide film.