Biodegradation of implant materials.

Various kinds of metals, ceramics, and polymers have been implanted into the human body to replace its failed or diseased parts. It is required that these biomaterials do not deteriorate in the living body, and that their mechanical, physical, and chemical properties are retained for the duration of service. However, almost all materials currently used for implantation more or less degrade in the biological environment. This article reviews several topics on the degradation and deterioration of metallic, ceramic, and polymeric biomaterials placed inside the body. The author conclusively remarks that biological effects on the mechanical properties of biomaterials should be studied more seriously by materials scientists and mechanical engineers in order to guarantee the safety and reliability of implant devices and artificial organs.