Ceramics, Glasses, and Glass-Ceramics: Basic Principles

Bioceramics are inorganic biomaterials that include crystalline ceramics, amorphous glasses, and glass-ceramics. Applications commonly include repair, replacement, or regeneration of bone or teeth, but are becoming broader. This chapter will consider nearly-inert bioceramics and those that are bioactive (and biodegradable), such as Bioglass and hydroxyapatite. Nearly-inert bioceramics tend to be used where a robust hard surface is needed, e.g., a joint replacement with articulating bearing surface or dental restoration. Bioactivity is regarded as the provocation of a beneficial biological response from the body’s host environment to the implanted devices. In the case of bioactive ceramics, glasses, and glass-ceramics, this has traditionally been regarded as the ability to form a direct bond with bone tissue without fibrous encapsulation. However, it is now recognized that ions released by bioceramics can stimulate and guide cells. This has extended “bioactivity” beyond bone applications, e.g., to wound healing.