Abstract
The purpose of this investigation was to evaluate the acceptability of the collagen-based xenograft ($Laddec^{(R)}$). Full thickness bone defects were prepared in the calvaria of the rats. In the experimental groups the bone defects were filled with a kind of collagen based xenograft. And bone defects, which left without filling, were used as control groups. Sequential sacrifice was performed at the 1st, 2nd, 4th, 8th, and 16th weeks of experiment. 1. At the 1st week of experiment, infiltration of chronic inflammatory cell was observed in all groups. In the experimental group, resorption of the xenograft was initiated. 2. At the 2nd week of experiment, infiltration of chronic inflammatory cells was decreased in all groups. In the experimental group, active resorption of xenograft and new bone formation from the periphery of the xenograft was observed. 3. At the 4th and 8th weeks of experiment, more resorption of the xenograft and new bone formation with calcification was observed in the experimental group. 4. At the 16th week of experiment, small bone trabecula was formed partially in the control group but that couldn't fill the whole bone defect. In the experimental group, more advanced resorption of xenograft and more new bone formation was observed. However mid portion of the xenograft was still remained without resorption. 5. From this experiment, we concluded that the collagen-based xenograft had some osteoconductive but no osteoinductive property. So the xenograft would be used for the bone defect filling material where rapid bone remodeling is not required.