BEHAVIOR OF CALCIUM-PHOSPHATE COATINGS WITH DIFFERENT CHEMISTRIES IN BONE

Calcium phosphate ceramic coatings with a hydroxyapatite chemistry app lied on the surface of dental implants eliminate the need for initial mechanical retention and decrease the time necessary for bonding the i mplants to the bone. Hydroxyapatite-coated implants retrieved from pat ients were found to be compatible and to have bonded strongly to the b one, but the coatings showed thinning because of partial or total loss of coating material. This study compared the behavior in bone of newl y developed fluorapatite and heat-treated hydroxyapatite coatings, wit h the clinically used hydroxyapatite coatings used as controls in expe rimental studies in dogs. The biologic responses to fluorapatite and h eat-treated hydroxyapatite coatings were the same as those to hydroxya patite coatings, and bone condensation around all coatings was histolo gically evident. However, the coating thickness of the fluorapatite an d heat-treated hydroxyapatite coatings remained stable with only minor changes during the observation period of 24 months.