[Relative gnotobiosis: a possibility for studying periodontal diseases in the rat].

An animal model was presented to study periodontal disease in Osborne-Mendel rats with depressed indigenous oral flora. In connection with the inoculation of an erythromycin-resistant strain A. viscosus Ny 1 E after 40 experimental days only the animals showed plaque formation, bleeding from the gingival sulcus upon gentle probing and severe alveolar bone loss. 56% sucrose in the diet counteracted the establishment of A. viscosus Ny 1 E in dental plaques. As a consequence plaque formation, gingival bleeding and bone loss diminished. Plaque formation, gingival bleeding and bone loss were correlated.