CORTICAL BONE INGROWTH IN GROOVED IMPLANTS WITH CALCIUM-PHOSPHATE COATINGS - A GAP MODEL STUDY

In in vivo experiments the gap healing of uncoated grooves and grooves coated with HA, HAH (heat treated hydroxylapatite) and FA was studied histologically and histometrically. Cylinders with grooves (0.25 mm, 0.50 mm, 0.75 mm or 1.0 mm depth) were implanted in cortical bone of goats for 3, 6 or 12 weeks. In the uncoated gaps after 3 weeks of implantation no bone ingrowth could be observed. Afer 6 weeks of implantation about 35% bone ingrowth was seen in the uncoated gap independent of gap depth. There was mostly no bone contact with the titanium surface. the presence of a coating enhanced bone ingrowth and initiated more bone contact. After 3 weeks of implantation there was more bone ingrowth and after 6 weeks the bone ingrowth and bone contact was increased, independent of the coating type. HAH showed the highest bone ingrowth. The bone ingrowth started from the periphery of the host bone.