This study evaluated the dose-response relationship between four increasing levels of fluoride from 1000 to 2500 ppm F as sodium monofluorophosphate (MFP) and three-year dental caries increments, as measured by DMFS, DMFT, and DFS-A on 4424 schoolchildren. The results indicated consistent linear decreases in all three dental indices as the dose level increased to 2500 ppm F MFP, with slopes (average reductions) of 0.32 in DMFS for an increase of 1000 ppm F, 0.13 in DMFT, and 0.17 in DFS-A when all children were evaluated, p < 0.03 for each index. For children 11 years and older at baseline, the slopes quadrupled, p < 0.01 for each index. Age and baseline DMFS were shown to be the most important covariates to control for in the statistical models. No differences in adverse reactions, or other safety problems, were observed at the different dose levels.