Experimental Rat Caries V. Effect of Fluorine on the Caries-Conduciveness of a Purified Ration

Abstract

Extensive carious destruction has been produced in Norway rats of the Long-Evans strain which were raised on a generally adequate purified ration, in spite of the addition of 6 or 25 p.p.m. of fluorine, as sodium fluoride, to the ration during the period before eruption of the teeth. The addition of these amounts of fluoride to the purified ration after the completion of tooth development did not result in any reduction in caries incidence within the experimental periods used in this study. The absence of caries which has been previously reported in rats fed natural stock diets during the period of tooth development cannot be satisfactorily explained by the fluoride content of those diets. While fluorides unquestionably modify the caries picture under certain conditions, these data suggest that there are other minerals or ratios of minerals which are major factors in determining the difference between sound and carious teeth.