MICROSCOPIC EVALUATION OF BONE-IMPLANT CONTACT BETWEEN HYDROXYAPATITE, BIOACTIVE GLASS AND TRICALCIUM PHOSPHATE IMPLANTED IN SHEEP DIAPHYSEAL DEFECTS

In order to compare morphological discrepancies in bone-implant contac t in vertebrates, cylinders of hydroxyapatite, bioactive glass and tri calcium phosphate were implanted in segmental defects of the tibia in sheep. Three types of visible bone-implant contact were observed micro scopically at 4 months after implantation, The trabecular web-like bon e-implant contact noted in tricalcium phosphate seemed superior to the disseminated patchy bone-implant contact in bioactive glass and the b uttressed bone-implant contact in hydroxyapatite with respect to both bone ingrowth and bioresorption of the implant. Differences of physico chemical properties on the surface among the three kinds of bioceramic implants probably give rise to different types of bone-implant contac t.