A pilot study of the relationship between caries experience and surface enamel fluoride in man

Fourteen hundred and forty-seven 12–16-yr-old subjects in selected fluoridated and non-fluoridated areas were assessed for caries experience (DMFS index) and enamel fluoride (biopsy technique). Fluoride was measured as log e mass F corrected to a standardized depth. A square root transformation of decayed, missing and filled surfaces (DMFS) was carried out in order to achieve homogeneity of variance for this variable across all levels of fluoride. A simple, linear relationship was found between log e mass F and √(DMFS). Taking age into account, the Pearsonian correlation was R = 0.40, corresponding to 16 per cent of the variance explained. Within communities the fluoride-caries relationship was consistent with the overall model but could not be demonstrated as securely because of the smaller sample sizes and the limited range of fluoride values at this level of disaggregation.