Residual Anticaries Effect of Topical Sodium Fluoride Applications in the Syrian Hamster

¹ U.S. Department of Health, Education, and Welfare, Public Health Service, National Institute of Dental Research, National Institutes of Health, Bethesda, Maryland

EXPERIMENT 1.—Fifty days after 13 daily 2-minute topical applications with a water soluble gel containing concentrated sodium fluoride had been made to the maxillary second molars of hamsters, dental caries was appreciably less than the cavitation that developed in the second molars of placebo-treated controls.

EXPERIMENT 2.—Twenty-five days after eight topical F^- gel treatments had been applied to newly erupted hamster maxillary third molars, a narrow band of demineralization but not cavitation could be detected in every F^--treated animal; however, severe cavitation occurred in the third molars of all controls, which did not receive the F^- treatments.

Both experiments indicate that a residual anticaries effect can be demonstrated in teeth of caries-infected hamsters, but that the series of topical F^- treatments administered was inadequate to afford complete protection against demineralization.