[Histo-pathology of the regenerating process in the tissue around the periodontally diseased teeth of beagle dogs. Clinical and histological analysis following flap surgery].

The regenerating process in tissue around periodontally diseased teeth (PDTs) and non-diseased teeth (NDTs) was studied with clinical and histological analysis following flap surgery. PDTs were prepared in the premolars of 7 beagle dogs by which surgically denuding the root surfaces by removing the alveolar bone. The denuded sites were covered with gutta-percha plates and gingival epithelial tissues and exposed to the oral environment for 4 weeks. Then flap surgery was performed on the PDTs. As control sites, the root surfaces of the NDTs were denuded by removing the alveolar bone at the time of flap surgery. The root surfaces of the PDTs and NDTs were planed with curette scalers at one root site but not at the other site. Clinical and histopathological findings were evaluated at fixed intervals for 32 weeks after surgery. Results of observation were as follows. 1. In the clinical evaluations, the gingival inflammation index, probing depth and attachment level were improved in the root planing (PR) group of both the PDTs and the NDTs, but in the non RP group of PDTs there was no improvement. 2. In the histologic observation, the position of the gingival margin, length of regenerated junctional epithelium, depth of gingival sulcus and the level of connective tissue attachment in the RP groups recovered in both the PDTs and the NDTs but not in the non RP groups.