OBJECTIVETo study the effects of artificial bone composite of bicoral, rhBMP-2 and PLA in repairing calvarial critical-size defects.

METHODSCalvarial defects in 24 rabbits were surgically made and then half of the defects were repaired with the artificial composite bone. Another half of them were repaired with bicoral/PLA composite and served as controls. Four rabbits in each group were sacrificed at 4, 8, 12 weeks after operation, respectively. The treatment effects were evaluated with scanning electron microscopy and mechanical strength testing.

RESULTSNew bone was observed not only in the periphery, but also inside the artificial bone in both groups, but earlier and more new bone formation was observed in treatment group compared with control group. The mechanical strength test showed that the artificial bone in two groups, which had same mechanical strength before implantation, had significant different mechanical strength after operation. The strength of the artificial composite bone was higher than that of controls and was same with normal rabbit calvarial bone.

CONCLUSIONThe artificial composite bone possess a highly repairing ability, and the healing in bone defects may be accomplished by both osteoinductive and osteoconductive mechanism. The material may be used as a good substitute for bone grafting.