Ceramics

Ceramics are inorganic materials that are composed of metallic and nonmetallic elements, which are bonded to each other with ionic or covalent bonds. Ionic bonds are strong and have melting temperatures higher than those of metals and polymers. Ceramics are produced from powdered materials by the application of heat. They are hard, strong, and brittle. Since they do not have free electrons, they are poor conductors of heat and electricity. There are numerous combinations of metallic and nonmetallic groups, and the most commonly known nonmetallic groups are oxides, hydrides, carbides, phosphates, sulfides, and silicates. Aluminum oxides, calcium phosphates, and titanium nitrides are included in this class. Carbon-based materials such as carbon, graphite, diamond, and graphene are sometimes classified as members of the ceramics group, but in this book, they are assigned to another chapter (Chap. 6 ). Ceramics are now extensively used in dentistry, in the production of orthopedic implants for the spine, and particularly in total hip implants due to their resistance against compression and wear. There are also bioceramics produced in various complex porous and moldable forms. In the USA, the estimated number of spinal fusion surgeries is about 300,000, and this is much more than the hip, knee, and shoulder implants combined [1]. Meanwhile, porcelain ceramics have been used in dentistry as crowns due to their stability in body fluids, high compressive strength, and good esthetic appearance.