Magnesium Based Biodegradable Metallic Implant Materials: Corrosion Control and Evaluation of Surface Coatings

Magnesium and magnesium alloys are currently being explored for biodegradable metallic implants. Magnesium’s biocompatibility, low density, and mechanical properties could offer advantages in the development of low-bearing orthopedic prosthesis and cardiovascular stent materials.Magnesium’s susceptibility to corrosion and increased hydrogen evolution in vivo compromises the success of its potential applications. Various strategies have been pursued to control and subsequently evaluate degradation.This review provides a broad overview of magnesium-based implant materials. Potential coating materials, coating techniques, corrosion testing, and characterization methods for coated magnesium alloys are also discussed.Various technologies and materials are available for coating magnesium to control and evaluate degradation. Polymeric, ceramic, metallic, and composite coatings have successfully been coated onto magnesium to control its corrosion behaviour. Several technologies are available to carry out the coatings and established methodologies exist for corrosion testing. A few magnesium-based products have emerged in international (European Union) markets and it is foreseen that similar products will be introduced in the United States in the near future.Overall, many coated magnesium materials for biomedical applications are predominantly in the research stage with cardiac stent materials and orthopaedic prosthesis making great strides.