The effect of demineralized intramembranous bone matrix and basic fibroblast growth factor on the healing of allogeneic intramembranous bone grafts in the rabbit

The aim here was to explore a new graft material that excludes the need to harvest autogenous bone from patients. Forty-two critical-size (10×15 mm) defects were created in rabbit mandibles bilaterally. Five groups of six defects each were grafted with autogenous endochondral (EC) bone, autogenous intramembranous (IM) bone, fresh-frozen allogeneic IM bone only, fresh-frozen allogeneic IM bone and demineralized bone matrix powder prepared from intramembranous bone (DBMIM) only, and fresh-frozen allogeneic IM bone and basic fibroblast growth factor (bFGF) mixed with DBMIM powder. The remaining defects were used as controls. Three weeks after surgery, the defects were retrieved for histological analysis. The amount of new bone formation was quantified by image analysis. No bone formed across the defect in the controls; 224% more new bone formed in defects grafted with composite allogeneic IM bone/DBMIM than in those grafted with allogeneic IM bone alone (p<0.001); 550% more new bone was formed in defects grafted with composite allogeneic IM bone/DBMIM/bFGF than in those grafted with allogeneic IM bone alone (p<0.001). The amount of new bone in the group receiving composite allogeneic IM bone/bFGF/DBMIM was more than that in autogenous EC bone group, and very close to that in autogenous IM group. The results show that a composite of fresh-frozen allogeneic IM bone and bFGF in DBMIM powder is a good graft material that warrants further clinical investigation.