ABSTRACT
Ceramics can be classi ed according to their atomic arrangement, that is, based on whether they are randomly arranged (amorphous) or arranged in an ordered structure (crystalline). An example of an amorphous ceramic is glass, and an example of a crystalline ceramic is porcelain. Their emergence dates back many centuries, and many ceramics are also used as biomaterials for implantation in the body. In today’s biomedical applications, bioceramic uses range from bone implants to biomedical pumps. Unlike the ceramics used for other applications, bioceramics must possess qualities that are mechanically, physically, and chemically compatible with host tissues. The desired properties of implantable bioceramics are that they should be nontoxic and noncarcinogenic, should not induce allergic reactions and in§ammatory responses, and should induce tissue regeneration and tissue integration. In addition to the atomic arrangement, bioceramics can be classi ed according to their reactivity, that is, based on whether they are bioinert, bioresorbable, or biosurface reactive. An example of a bioinert bioceramic is alumina, which is used in the fabrication of total hip replacement prostheses and dental crowns. Bioglass, an example of a biosurfacereactive bioceramic, reacts with biological §uids to form a bioactive carbonate apatite layer on its surface. Among the many different bioceramics, the most popular ceramics used in medicine are the calcium phosphates, which are also classi ed as bioresorbable ceramics. For example, the successful use of calcium phosphate reagent was reported in the 1920s, for the repair of human bone defects (Albee 1920). In the 1970s, porous tricalcium phosphate and dense hydroxyapatite, two different phases of calcium phosphate ceramics, were reported to be successfully used in the repair of periodontal defects and as tooth-root replacements, respectively (Nery et al. 1975; Denissen 1979). This chapter will focus on some of the calcium phosphate biomaterials commonly used in today’s medical industry.
