[The histopathological study of periodontal tissue regeneration using atelocollagen membranes]

In an attempt to promote periodontal tissue regeneration following periodontal surgery, an experimental study was conducted by applying the guided tissue regeneration (GTR) technique to a cross-linked atelocollagen membrane. The palatal gingiva of maxillary first molars of rats were dissected and the cementum was removed by curettage. An atelocollagen membrane was implanted into the site of dissection in the experimental group, while the control group received no implant. The wound healing processes in two groups were examined by histopathological methods, including histometric analysis of the cells and histological measurement of the regenerated periodontal tissue, 1, 3, 5, 7, 14 and 21 days, and 1, 2, 3 and 4 months after the implantation. The results were as follows. 1) Implantation of the atelocollagen membrane did not enhance or prolong the inflammatory reaction, indicating possible involvement of inflammatory cells and macrophages in the membrane absorption. 2) In the experimental group, epithelial downgrowth was markedly inhibited and fiber bundles of the gingival connective tissue were clearly arranged vertical to the root surface. 3) The experimental group showed a significant increase in new cementum formation 2 months after surgery compared with the control group. Root resorption was seldom observed in either group during the study period. The above results indicate that the GTR technique using an atelocollagen membrane may provide an effective method to promote periodontal tissue regeneration after periodontal surgery.