Cobalt–chromium–molybdenum (CoCrMo) alloys are widely used in orthopedic implants due to their mechanical strength and corrosion resistance. However, concerns remain about the ion release from these alloys when exposed to the biological environment, which can lead to adverse reactions such as inflammation or metal hypersensitivity. This study investigates the ion release behavior and biocompatibility of the CoCrMo-0.4 Ti alloy, comparing uncoated and titanium nitride (TiN)-coated samples. The TiN coating was applied via the physical vapor deposition (PVD) method. Characterization techniques, including X-ray diffraction (XRD), scanning electron microscopy (SEM) along with energy dispersive spectroscopy (EDS), atomic force microscopy (AFM), and X-ray photoelectron spectroscopy (XPS), were used to assess the coating quality and surface properties. The ion release tests in Ringer’s solution over 90 days revealed significantly lower cobalt (Co) and nickel (Ni) release from TiN-coated samples compared to uncoated ones. In both cases, chromium (Cr) was undetectable. Biocompatibility assessment via MTT assays demonstrated higher cell viability for TiN-coated samples than uncoated samples, confirming the improved biocompatibility provided by the TiN coating. These findings highlight the effectiveness of TiN coatings in reducing ion release and enhancing the performance of CoCrMo alloys in biomedical applications.
Sadeq et al. (Thu,) studied this question.