The Effect of Penicillin on Dental Caries in Rats Fed on a Coarse Corn Diet

Abstract

126 rats were fed a coarse corn caries-producing diet (Hoppert) beginning at 25 to 30 days of age and continued for 110 days at which time the rats were sacrificed. Additions of penicillin and sucrose were made to the water supply. The number of carious teeth produced in the water control group was not reduced significantly by adding 5 u. of penicillin per ml. of water. In the sucrose control group which was given sucrose, 1.5% in water, 22.5% of the teeth became carious. When the 1.5% sucrose soln. was supplemented with 2 u. of penicillin per ml., 16.6% of the teeth became carious, or a reduction of 26%. To another group 5 u. of penicillin per ml. were added to 1.5% sucrose soln., and only 9.3% of the teeth became carious, or a reduction of 59%. As increments of penicillin were added, the frequency of lactobacilli in the rat mouth flora was decreased and Bacillus lactis aerogenes was observed more frequently.