Dental Effects of Exposure to Fluoride-Bearing Dakota Sandstone Waters at Various Ages and for Various Lengths of Time

Abstract

During the winter of 1947-48, mirror-and-explorer dental examinations were given 2140 white elementary and high school children of Mitchell, S. Dakota. Among them were 297 migrant children with previous exposure to a fluoride-bearing water. Those whose exposure had terminated before eruption of the first permanent molars showed caries-inhibitory effects which persisted for a time but were virtually lost by the age of 14-16 yrs. In migrants 13-17 yrs. of age with fluoride exposure beginning at birth, tooth types with F exposure only during the period of calcification presented slight evidence of caries inhibition, which was marked only when F exposure had continued for some time after eruption. It is suggested that the fluorides inhibit dental caries when incorporated into teeth either during calcification or after eruption; and that the inhibitory effect tends slowly to be lost and henoe requires periodic or continual renewal for a max. and lasting effect.