Studies, in the Rat, of Susceptibility to Dental Caries

Abstract

In the first report in this series (20), it was noted that enamel hypoplasia occurred in incisors of rats on a low-Ca vitamin-D-free diet, but that apparently only recently formed enamel was affected, molar teeth escaping the deformity. The emphasis placed by Mellanby (15) on possible relationships of enamel defects to dental caries suggested the desirability of attempting to produce defective molar-enamel in rats by dietary means. Since enamel calcification of rat molars is complete at a very early age, it appeared desirable to feed a deficient diet to mothers during pregnancy and lactation, and then to continue the young under the same dietary conditions. Dental effects of this and other conditions, embodying possible factors in caries etiology, form the basis of the present report. EXPERIMENTAL METHODSThe plan followed in these experiments is represented in table 1. The first letter in the "designation" (last column) indicates the mother's diet; the second and third, the diet of the young after weaning.2 One group of mothers (N) was maintained on an optimal diet to provide a normal standard of growth and tissue structure. Of the groups on the basal test-diet,

The effect of ‘trace elements' on experimental dental caries in the albino rat

“…For caries evaluation, in the first experiment, the method of Cox, Dodds, Dixon and Matuschak (1939) was used, but it was difficult to maintain accuracy with the 1 to 10 grading scale of Rosebury, Karshan and Foley (1933) employed in this method. In all other experiments, the caries evaluation method of Carr (1954) has been used and has proved reliable yet simple.…”

A Method of Recording and Scoring Gross Carious Lesions in the Molar Teeth of Syrian Hamsters'

“…However, caries activity in the albino and hooded rat seems to be more related to the physical nature of cereal constituents of the diet than to nutritional ingredients (6,7,8) and shows a definite predilection for the mandibular teeth (7,8,9,10). These facts increase the problem of scoring and evaluating the decay.…”

“…Although proximal surfaces are not considered, this is a consistent omission that appears to be no greater than those for other systems using selective areas (4,5) or limited numbers of teeth (6). As the extent of cavitation is not fully indicated by the number of unit areas affected, provision is made to evaluate depth.…”

“…Since only lesions in which fracture has played no part may. be comparable to those observed in human teeth, a completely satisfactory evaluation of the caries experience requires histological study (4,6).…”

Incidence of dystrophies caused by fluorine in organs regulated by the parathyroid glands

“…There is a divergence of opinion with regard to the r6le which avitaminosis plays in producing dental lesions. Such lesions have been observed in experimental rats fed on diets deficient in vitamin A (Wolbach& Howe, 1925,1933a, vitaminC (Howe, 1920(Howe, , 1922Hojer, 1924;Wolbach & Howe, 1926) and vitamin D (Mellanby, 1929(Mellanby, , 1930Becks & Ryder, 1931;Rosebury & Foley, 1934), as quoted by Thoma (1941). The teeth lose their normal orange pigmentation, acquire a chalky white appearance and become brittle; they may jies caused by fluorine become so loose that they can be pulled out with the fingers.…”