ABSTRACT
This chapter reviews the techniques for making blocks of calcium phosphate ceramic, large enough to be used clinically. Ceramics are most often prepared by preforming a slurry of powder and liquid into a shape or a mold and increasing the temperature to a point where the individual powder particles fuse more or less together, depending on temperature and time. Cells of mesenchymal origin, macrophages, and giant cells are observed, sometimes with ceramic particles in their cytoplasm. Generally, decrease of strength of brittle ceramic materials is caused by slow or subcritical crack growth, occurring under stress, sometimes assisted by environmental factors. Biological properties are somewhat more difficult to assess in terms of microstructure, crystallinity, or other variables such as type of animal or place of implantation. A simple process of pressing and subsequent sintering suffices to produce a material with mechanical properties almost identical to those of dental enamel, a tissue which can be considered as dense apatite.
