COMPARATIVE-STUDY OF THE OSTEOINDUCTIVE PROPERTIES OF BIOCERAMIC, CORAL AND PROCESSED BONE-GRAFT SUBSTITUTES

This study compared the osteoinductive properties of six different bon e graft substitutes: Pyrost(R), natural coral, Callopat(R), Surgibone( R), demineralized Surgibone(R) and demineralized rat bone. The materia ls were implanted heterotopically, in the abdominal musculature of rat s, and the results evaluated histologically at 3 and 6 wk post-implant ation. Surprisingly, the results showed that both the demineralized ra t bone and demineralized Surgibone were less osteoinductive than might be believed from the literature. Mineralized grafts showed no sign of new bone formation and exhibited variable resorption patterns. A laye r of what appeared as dense calcification was seen around the coral im plant. The most intense inflammatory reactions were exhibited with the xenografts Surgibone and demineralized Surgibone, indicating persiste nt immune responses. Coral and Pyrost elicited no marked inflammatory response, and this was attributed to the negligible amounts of protein present in these materials.