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Bioactive Glasses and Glass-Ceramics
Introduction
Glass-ceramics are an important class of materials that have been commercially quite successful. They are polycrystalline materials produced by the controlled crystallization of glass. They are composed of randomly oriented crystals with some residual glass, typically between 2 and 5 percent, with no voids or porosity. Glass ceramics found wide applications as dielectric materials, machinable materials, biomaterials… etc.
Ceramics, glasses, and glass-ceramics include a broad range of inorganic/nonmetallic compositions. In the medical industry, these materials have been essential for eyeglasses, diagnostic instruments, chemical ware, thermometers, tissue culture flasks, and fiber optics for endoscopy. Insoluble porous glasses have been used as carriers for enzymes, antibodies, and antigens, offering the advantages of resistance to microbial attack, pH changes, solvent conditions, temperature, and packing under high pressure required for rapid flow. Ceramics are also widely used in dentistry as restorative materials such as in gold-porcelain crowns, glass-filled ionomer cements, and dentures.
This section focuses on ceramics, glasses, and glass-ceramics used as implants. Although dozens of compositions have been explored in the past, relatively few have achieved clinical success. The science and practice of biomaterials examines differences in processing and structure,