contents of caries.dat The data show the caries experience of 7257 children 12-14 years of age in 21 communities according to the fluoride concentration of their public water supply. DMF denotes "Decayed, Missing or Filled". locality which community (numbered 1-21) DMFteeth: DMT teeth per 100 children (so 236 implies an average of 2.36 affected teeth per child) Fluoride Fluoride Concentration in aprts per million (ppm) Source: can no longer remember! but suspect these data date from before first community trials of water fluoridataion i.e. trials where the fluoride was added to the water. In the 21 towns above, the flouride is naturally occurring.