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Combined Effect of Trace Elements and Fluoride on Caries: Changes Over Ten Years in Northwest Ohio (U.S.A.)

Dental caries examinations were carried out in an area of low caries prevalence, ascribed to a combined effect of fluoride and other trace elements. Repeat examinations in 1978 on lifelong resident children aged from 12 to 14 yr showed caries distribution patterns to be essentially the same as those found in a previous study in 1968. Some changes in DMFS scores had occurred, which were associated with changes in the strontium content of the drinking water; low caries levels were significantly associated with high strontium concentrations.