MICROORGANISMS ASSOCIATED WITH DENTAL CARIES IN THE COTTON RAT

¹ Departments of Biochemistry and Agricultural Bacteriology, College of Agriculture, University of Wisconsin, Madison, Wis.

Correlation was obtained between the incidence and extent of carious lesions and the bacterial counts of teeth from cotton rats fed diets containing low levels of honey and sucrose. The incidence and extent of caries, and the corresponding bacterial counts, were much greater when honey replaced sucrose at similar levels (2 to 10 per cent) in these rations. No significant difference could be noted either in incidence and extent of carious lesions or in bacterial counts when the levels of sucrose or honey in the ration were varied from 2 to 10 per cent.

Organisms isolated from carious teeth were identified as lactobacilli and enterococci. Approximately four times more enterococci than lactobacilli were found in carious teeth.

The strong proteolytic action of the enterococci found tends to emphasize the importance of organic matrix of the tooth and its relationship to dental caries.