Abstract
The effects of different treatments on periodontal healing after flap surgery in rats were determined. A mucoperiosteal flaps were raised on the maxillary molar teeth. After lead foil and a sponge were inserted between the root surface and palatal flap, they were ligatured with nylon thread, and the flaps were sutured. Two weeks later, the same operation was carried out at this site again, producing experimental periodontal pockets which remained for two weeks after removal of the lead foil and the sponge.
Flap surgery was performed on these experimental periodontal pockets. In group I, root planing was carrid out completely, but in group II, there were received no treatment. Animals were sacrificed immediately before surgery, and 3 days and 1, 2, 4 and 6 weeks after surgery, and sections were examined in light and electron microscopes.
In group II, histological examination showed a dense layer on the root surface, and epithelial downgrowth was revealed in this layer. The reduction in inflammatory cells and the regeneration of gingival connective tissue were delayed as compared with group I. In addition, the collagen fibers were prevented from extending from the periodontal ligament, and extreme root resorption was seen on the root surface. There was no difference in regeneration of the alveolar bone between group II and group I, and the degree of regeneration of the cementum was greater in group II than group I, at the ealy healing stage.
