Morphological changes of autoclaved autogenic bone implantation and autoclaved autogenic bone supplemented with allogenic demineralized bone matrix in rat parietal bone.

The healing process of resected, autoclaved (121 degrees C, 20 minutes) and re-implanted bone in the rat parietal bone was compared with that of autoclaved bone that was supplemented with allogenic bone matrix (AAA-bone), using a scanning electron microscope and a light microscope. In the implant without AAA-bone, bone union and replacement of the autoclaved bone was seen at 2 weeks after implantation. There was no evidence of any inflammatory reaction around the autoclaved bone. The implant was gradually replaced by the new bone. In the implant with AAA-bone, the new bone formation around the implanted bone was more abundant than that of the implant without AAA-bone. An inflammatory reaction was also observed after 1 week. The replacement of the implant with AAA-bone was inferior to the nonsupplemented group. The reason for the poor replacement was the disturbance of the blood supply in the implant by abundant new bone formation. In these results, the autoclaved bone re-implantation was an excellent bone substitute with osteoconductive ability and biocompatibility. The implantation with AAA-bone was good for the new bone formation, but the position and the technique of supplement with AAA-bone have to be more deeply investigated.