Properties of Osteoconductive Biomaterials: Calcium Phosphates

Bone is formed by a series of complex events involving the mineralization of extracellular matrix proteins rigidly orchestrated by cells with specific functions of maintaining the integrity of the bone. Bone, similar to other calcified tissues, is an intimate composite of the organic (collagen and noncollagenous proteins) and inorganic or mineral phases. The bone mineral idealized as calcium hydroxyapatite, Ca10 (PO4)(6)(OH)2, is a carbonatehydroxyapatite, approximated by the formula: (Ca,X)(10)(PO4,HPO4,CO3)(6)(OH,Y)2, where X are cations (magnesium, sodium, strontium ions) that can substitute for the calcium ions, and Y are anions (chloride or fluoride ions) that can substitute for the hydroxyl group. The…