Preparation-induced stability of bioactive apatite coatings
Denissen, H.W.; Kalk, W.; de Nieuport, H.M.; Mangano, C.; Maltha, J.C.
International Journal of Prosthodontics 4(5): 432-439
1991
ISSN/ISBN: 0893-2174 PMID: 1667360 Document Number: 371410
The stability of the bioactive surface is a major concern in the chemical and physical design of apatite ceramic coatings. In clinical studies, no sintered-hydroxyapatite bulk coating material was present in the surrounding bone tissue after loading periods up to 11 years. In in vitro studies, hydroxyapatite plasma-sprayed coatings dissolved considerably, possibly because of loss of crystallinity during the plasma-spraying procedure. A heat treatment at 600 degrees C reconstituted the crystallinity and promoted the transformation of alpha-tricalcium phosphate into the more stable beta-tricalcium phosphate. Fluorapatite coatings did not lose their crystallinity and had the added advantage of stability as a result of the fluoride ion.