Metals and medicine

Abstract

The research and development of metallic biomaterials and their future prospects are overviewed. Approximately 80% of implant devices and 95% of orthopedic devices are still made of metal, and metallic materials therefore continue to play an important role in medical treatment. Current research efforts in metallic biomaterials can be summarized into the following categories: the elucidation of interfacial reactions between metals and tissues (including evaluations of safety and corrosion resistance); the development of new surface treatment techniques (including the control of surface morphology); the development of new alloys; and the development of new manufacturing processes. Interfacial reactions between metals and living tissues are discussed from the viewpoints of biocompatibility and biofunction, corrosion resistance, and calcium phosphate formation on the surface oxide film. The transitions taking place in the surface treatments for osteogenesis, soft tissue adhesion, antibacterial property, and antithrombotic property are summarized, followed by a discussion of their future prospects. In addition, the concept of a dual-functional surface is explained. A review is done of zirconium alloys that decrease magnetic resonance imaging (MRI) artifacts, Ni-free austenitic stainless steel, high-pressure torsion and sliding processing, and additive manufacturing. Finally, the future of biomaterials research is considered.