Effect of fluoridated sucrose on rat caries

The present study was designed to test the effect of frequent pulses of low fluoride levels on rat caries when supplied in a standardized cariogenic rat diet containing 67% sucrose (MIT-200). The test diets were variants of Diet MIT-200 in which the sucrose component had been fluoridated with NaF solution resulting in total concentrations of 0 (control), 2, 3, 5, 10, or 20 ppm fluoride in the final diets. Rats received one of the test lots 17 times daily in a programmed feeding machine beginning at age 22 days, and were inoculated with Streptococcus mutans at age 23, 24, and 25 days. After 5 weeks, the rats were sacrificed and their mandibular molars scored for number and severity of sulcal, buccolingual, and proximal caries. Frequent daily pulses of as little as 2 ppm fluoride in dietary sucrose were effective in significantly (p less than 0.01) reducing buccolingual rat caries.