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A natural mineral structure that the crystal lattice of bones and teeth ( i.e., amorphous h.) closely resembles; used in chromatography of nucleic acid s; also found in pathologic calcifications ( e.g., atherosclerotic aortas). SYN: hydroxylapatite.
- amorphous h. containing ion contaminants ( e.g., 6–8% CO32−, 3–5% Mg2+, F−, Cl−, etc.); found in mineralized connective tissue ( e.g., bone, dentin, cementum). SYN: poorly crystalline h..
- poorly crystalline h. SYN: amorphous h..
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hy·droxy·ap·a·tite hī-.dräk-sē-'ap-ə-.tīt or hy·drox·yl·ap·a·tite -sə-'lap-ə-.tīt n a complex phosphate of calcium Ca5(PO4)3OH that occurs as a mineral and is the chief structural element of vertebrate bone
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n.
1. the crystalline component of bones and teeth, consisting of a complex form of calcium phosphate.
2. a biocompatible ceramic material that is a synthetic form of natural hydroxyapatite. Some joint replacement prostheses are coated with synthetic hydroxyapatite, which encourages bone to grow on to the implant. The material is also used in some forms of middle-ear surgery.
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hy·droxy·ap·a·tite (hi-drok″se-apґə-tīt) an inorganic compound found in bone matrix and teeth, giving them rigidity. Compounds having this approximate chemical formula are synthesized for use as calcium supplements (see tribasic calcium phosphate, def. 2) and prosthetic aids (see durapatite). Called also hydroxylapatite.Medical dictionary. 2011.