Preparation-induced stability of bioactive apatite coatings.
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.
Denissen
H W
HW
University of Nijmegen, The Netherlands.
Kalk
W
W
de Nieuport
H M
HM
Mangano
C
C
Maltha
J C
JC
D000818:Animals; D001031:Apatites / Q000737:chemistry*; D001673:Biodegradation, Environmental; D002130:Calcium Phosphates; D002516:Ceramics / Q000737:chemistry; D015921:Dental Implants; D004285:Dogs; D004355:Drug Stability; D017886:Durapatite; D005500:Follow-Up Studies; D006358:Hot Temperature; D006801:Humans; D006882:Hydroxyapatites / Q000737:chemistry*; D008422:Materials Testing; D013499:Surface Properties; D014961:X-Ray Diffraction
D001031:Apatites; D002130:Calcium Phosphates; D015921:Dental Implants; D006882:Hydroxyapatites; C485828:alpha-tricalcium phosphate; C485830:tetracalcium phosphate; C485838:calcium phosphate, monobasic, anhydrous; D017886:Durapatite; C020243:calcium phosphate; C485829:calcium phosphate, dibasic, anhydrous; C025105:fluorapatite