- The hard glistening substance covering the exposed portion of the tooth. In its mature form, it is composed of an inorganic portion made up of 90% hydroxyapatite and 6-8% calcium carbonate, calcium fluoride, and magnesium carbonate, the remainder comprising an organic matrix of protein and glycoprotein; structurally, it is made up of oriented rods each of which consists of a stack of rodlets encased in an organic prism sheath. SYN: enamelum [TA], substantia adamantina, substantia vitrea. [M.E., fr. Fr. enamailer, to apply e., fr. en, on, + amail, e., fr. Germanic]- dwarfed e. SYN: nanoid e..- mottled e. alterations in e. structure due to excessive fluoride ingestion during tooth formation; varies in appearance from small white opacities to yellow and black spotting.
* * *enam·el in-'am-əl n the intensely hard calcareous substance that forms a thin layer partly covering the teeth of many vertebrates including humans, is the hardest substance of the animal body, and consists of minute prisms secreted by ameloblasts, arranged at right angles to the surface, and bound together by a cement substance compare CEMENTUM, DENTIN
* * *n.the extremely hard outer covering of the crown of a tooth. It is formed before tooth eruption by ameloblast and consists of crystalline hydroxyapatite.
* * *enam·el (ə-namґəl) [O.F. esmail] 1. the glazed surface of baked porcelain, metal, or pottery. 2. any hard, smooth, glossy coating. 3. dental e.
Medical dictionary. 2011.