Experimental gingivitis in ODU plaque-susceptible rats. III. Toxic activity of the rat dental plaque.

The toxicity tests of the dental plaque from ODU plaque-susceptible rats showed strong lethal effect on mice, and abscess forming effect on guinea-pigs. Bacterial cells isolated from the rat dental plaque also showed strong toxicity on both animals and capillary permeable activity on rabbits. Among these bacterial cells, Corynebacterium showed the strongest toxic effects on these animals. These facts suggested an important role of the dental plaque on initiation and development of gingivitis and that especially Corynebacterium may play an important role on gingivitis in ODU plaque-susceptible rats.