SHORT-TERM AND LONG-TERM ANIMAL STUDIES WITH A PLASMA-SPRAYED CALCIUMPHOSPHATE-COATED IMPLANT

A commercially available hydroxyapatite(HA)-coating was investigated i n a 4- and 24-week animal study. HA-coated and uncoated commercially p ure (c.p.) titanium threaded implants were inserted in rabbit tibia an d femur. Qualitative histology showed giant cells and macrophages arou nd both types of implants. Histomorphometry demonstrated significantly more bone in contact to the HA-coated specimens at both follow-up per iods. In contrast, bone area measurements (the amount of bone inside a nd/or outside the threads) revealed significantly higher percentages o f bone around the uncoated c.p. titanium controls after 6 months of fo llow-up. The inferior amount of bone around the HA-coated implants in the longer-term perspective may relate to macrophage-induced resorptio n.