Possible Relationship Between the Fluorine Content of Enamel and Resistance to Dental Caries, JDent Res

That the susceptibility and immunity of teeth to caries is to be accounted for, at least in part, by differences in composition is a hy-pothesis that has long been attractive. The evidence for the claims (7, 8) that such differences exist have failed of confirmation. We (3) found enamel and dentin fractions prepared from sound and carious teeth to possess compositions, with respect to the calcium, phosphorus, magnesium, and carbonate contents, which were not significantly different. LeFevre and Hodge (9) found whole tooth inorganic substance prepared from carious specimens to differ from that obtained from sound teeth only with respect to a slightly higher moisture content of carious tooth substance.2 Without regard to the data to be presented below, there is evidence that marked changes in some of the properties of enamel accompany changes in its fluorine content. The amount of fluorine in mottled enamel is relatively slight (4) in comparison to the total inorganic material; yet it produces, or is accompanied by, profound changes in the appearance and properties of the enamel. In this connection it is worthy of mention that it has not been demonstrated that mottling of enamel is due entirely to the effect of fluorine combined in the inorganic phase and is possible that the condition is produced, in part, by the operation of the fluoride ion on enzymes during the calcification of the enamel. The effect of fluorine added to the diet on the quality of the teeth of rats first observed by Schulz an