Dental ceramics are materials that are part of systems designed with the purpose of producing dental prostheses that in turn are used to replace missing or damaged dental structures. The literature on this topic defines ceramics as inorganic, non-metallic materials made by man by the heating of raw minerals at high temperatures. [1]
Ceramics and glasses are brittle, which means that they display a high compressive strength but low tensile strength and may be fractured under very low strain (0.1%, 0.2%).
As restorative materials, dental ceramics have disadvantages mostly due to their inability to withstand functional forces that are present in the oral cavity. Hence, initially, they found limited application in the premolar and molar areas, although further development in these materials has enabled their use as a posterior long-span fixed partial prosthetic restorations and structures over dental implants. [2] All dental ceramics display low fracture toughness when compared with other dental materials, such as metals. [3]
Metal ceramic systems combine both the exceptional esthetic properties of ceramics and the extraordinary mechanical properties of metals. [4] Some metals used as restorative materials in dentistry may constitute a problem for some patients. These problems may reveal themselves as allergies, [5] gum staining [6],[7] and release of metallic ions into the gingival tissue [8] and the gingival fluid. [9] These drawbacks, as well as the search for more esthetic materials by patients and dentists, have stimulated research and development of metal-free ceramic systems.
The main objective of this work is to review ceramic dental materials, including their most relevant physical and mechanical properties.