Dental Caries in the Cotton Rat. IV. Inhibitory Effect of Fluorine Additions to the Ration. ∗

Abstract

Summary

Some inhibition of caries resulted when 45, 90, or 135 p.p.m. of fluorine were ingested as supplements to a sucrose basal ration. Depigmentation of the incisors appeared when 45 or more p.p.m. of fluorine were incorporated in the diet while mottling of the third molars occurred when 225 or more p.p.m. were fed. The ingestion of 225 or 450 p.p.m. of fluorine caused a 90%. decrease in caries incidence. Thus the amount of fluorine necessary to inhibit caries to this degree was sufficiently high to cause mottling of the developing teeth.

The inhibitory effect of dextrin upon caries development could not be explained on the basis of its fluorine content.