OSTEOINDUCTION WITHIN PEO PBT COPOLYMER IMPLANTS IN CRANIAL DEFECTS USING DEMINERALIZED BONE-MATRIX/

This study was undertaken to assess the osteoinductive effect addition of demineralized bone matrix (DBM) gel has, on the behaviour of osteo conductive bone-bonding PEO/PBT copolymer (Polyactive(R)) implants. Cr anial defects in rats were filled with these composites to study bone formation in comparison with several controls after 2 and 8 weeks surv ival time. Osteogenesis was qualitatively evaluated by using light- an d transmission electron microscopy as well as backscatter electron ima ging. Quantification of the amount of bone ingrowth was performed by u sing a computerized image analysis system. Initially, rapid calcificat ion was observed in the polymer and DBM, followed by formation of new trabecular bone around the demineralized bone fragments. Bone ingrowth in implants consisting of plain copolymer was less than expected base d on previous research, but the addition of demineralized bone matrix gel resulted in a significantly greater amount of new bone formation i n the defects. We concluded that the application of DBM-gel to Polyact ive(R) implants had a beneficial effect on the amount of new bone form ation in this material. This procedure combines the osteoinductive pot ential of DBM with the mechanical and bone-bonding properties of a cop olymer, thus opening the way to the development of a line of osteoacti ve composite implants with good surgical handling properties.