Periodontal disease in the rice rat: IV. The effects of antibiotics on the incidence of periodontal lesions

Abstract

Two hundred fourteen rice rats were used in four experiments to test the prophylactic and curative abilities of penicillin and streptomycin on the periodontal syndrome. Supplements of 0.05 per cent penicillin or of 0.05 per cent streptomycin to ration 4 or ration 700 throughout the twenty-one-week experimental period caused major reductions in the number and extent of soft tissue lesions but much smaller reductions in the amount of alveolar bone resorption. A supplement of 0.01 per cent penicillin to ration 700 was also highly effective in the prevention of periodontal lesions, while a comparable supplement of streptomycin was much less effective. Supplements of 0.05 per cent penicillin or 0.05 per cent streptomycin to ration 700 during the last seven weeks of the experimental period were much less effective. Penicillin caused a moderate amount of healing of existing lesions of the soft tissues, while streptomycin did not encourage healing but did prevent further progression of soft tissue lesions. Neither had any striking influence on the resorption of alveolar bone in the curative test.