THE RELATION OF STREPTOCOCCI, LACTOBACILLI, AND THE GENERAL ORAL AND FECAL FLORA TO THE PROGRESSION OF DENTAL CARIES IN THE HAMSTER

¹ National Institute of Dental Research, National Institutes of Health, Public Health Service, U. S. Department of Health, Education, and Welfare, Bethesda, Md., and University of Rochester, School of Medicine and Dentistry, Rochester, N. Y.

1. A technic for repeated bacteriologic samplings of hamster saliva and correlative dental examinations has been described.

2. No positive relationship was found between salivary streptococci and dental caries in either male or female hamsters.

3. No correlation was observed between salivary lactobacilli and dental caries in females.

4. In male hamsters a positive relationship was noted between lactobacilli and dental caries, but only after very extensive development of lesions.

5. The final mean caries scores of males and females in this study were not significantly different.

6. The ecologic relations of the streptococci and lactobacilli were widely different in the mouth as compared to the feces.

7. Microscopic examination of oral and fecal smears indicated that the streptococci and lactobacilli were a relatively small part of the total flora and that a great percentage of the organisms, such as fusiforms, bacteroides, large coccal organisms other than streptococci, etc., have not been cultured.