ISSN:
0021-9304
Keywords:
carbonate
;
hydroxyapatite
;
substitution
;
precipitation
;
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Medicine
,
Technology
Notes:
Carbonate substitution in the apatite crystal lattice can occur in either the hydroxyl or the phosphate sites, designated as A or B type, respectively, and previous investigations generally have described precipitated carbonate hydroxyapatite as being B type on the basis of infra red and X-ray data. This paper documents the effects of two precipitation variables, namely temperature and bicarbonate ion concentration, on the morphology, phase composition, and calcium, phosphorus, and carbon contents of precipitated carbonate hydroxyapatite. Variations in both temperature and bicarbonate concentration could yield either acicular or spheroidal crystals. X-ray diffraction and infra red spectroscopy indicated the presence of carbonate in the A site for low carbonate contents (〈 4 wt%), and at higher carbonate contents (〉 4 wt%), the carbonate was located predominantly in the B site. On the basis of these observations and chemical analyses, a new AB carbonate substitution mechanism is proposed that better describes the experimental data than the B-type models used previously. © 1998 John Wiley & Sons, Inc. J Biomed Mater Res, 41, 79-86, 1998.
Additional Material:
7 Ill.
Type of Medium:
Electronic Resource
Permalink
