Relationships among fluoride concentration in enamel, degree of fluorosis and caries incidence in a community residing in a high fluoride area.

The caries inhibitory effect of optimally fluoridated drinking water is well documented. Communities are often exposed to naturally fluoridated water with F content exceeding the optimal level. The purpose of this study was to determine the relationship between enamel fluoride, degree of fluorosis (DEGF) and caries incidence (DMFT) in an endemic fluoride area. Eighty-five 14- to 16-year-old children (37 males and 48 females) who were born and had been living continually in the town of Kenhardt in South Africa were selected for this study. The fluoride content of the common water supply is 3.2 ppm F. The DMFT and DEGF were determined clinically. Acid etch biopsies were carried out on both maxillary central incisors of each subject. Ca and F analysis were carried out and mass enamel expressed in microgram and mass F in pg. Data transformations to loge mass F (1nF), loge mass En (1nEn) and square root DMFT were made. The 1nF values were corrected to a standardized depth of 10 micrometer (208.6 microgram enamel equivalent mass) by covariance analysis. Correlations between the parameters square root DMFT, 1nF ad DEGF were calculated, adjusting for the sex of the individual. The correlations were as follows: (formula: see text). A positive association among the three parameters was established.