INFLUENCE OF MAGNESIUM ON THERMAL STABILITY OF CARBONATED HYDROXYAPATITE

摘要

An important biologically element in the bone tissue is magnesium, whose main role is as an enzyme cofactor [37]. Mg is a minor constituent of dentine, enamel and bone, and has been associated with dental caries [37]. It may influence bone quality in osteodystrophy [27]. The bone magnesium content was shown to be significantly lower in the aplastic bone disorder [27]. Magnesium easily replaces calcium in the apatite lattice and directly influences, or even control, the crystallization processes of HA [154,155]. The partial substitution of calcium by a cation of considerably different size, i.e. magnesium (0.86 A) [156], significantly destabilizes the apatite lattice resulting in tricalcium phosphate crystallization [33]. The thermal stability of Mg-containing CHA is supposed to depend on the synthesis method and route, and on magnesium content. For example, it has been pointed out that the vacancy level is dependent on the CHA preparation conditions.