The prevalence of dental fluorosis in relation to water or salt fluoridation and reported use of fluoride toothpaste in school-age children

Abstract

To compare prevalence of dental fluorosis (DF) in permanent teeth in children whose domestic water supply was fluoridated since birth with that in a community where fluoridated salt was available. A second aim was to analyse the relationship between DF prevalence and reported use of fluoride toothpaste in early childhood. Cross-sectional study. A representative, random sample of 12-year-old children was examined in water fluoridated Dublin (Ireland) and non-water fluoridated Freiburg (Germany), where fluoridated salt was available. DF was recorded using the Dean's Index. The child's early experience of toothpaste use was recorded using a questionnaire. 377 children in Dublin and 322 children in Freiburg were examined. In Dublin 11.7% of the whole sample had a 'Questionable' level of DF, 9.8% had 'Very Mild', 3.7% had 'Mild' and 0.3% had 'Moderate' fluorosis. The corresponding percentages in Freiburg for all children were 10.9%, 4.0%, 3.4% and 0%. The results suggest that children in Dublin started brushing their teeth at an older age than in Freiburg, but no difference in DF levels was found between 'early' and 'late' users. Fisher's test revealed that the difference in DF levels between the two populations was statistically significant (p=0.03). The prevalence of aesthetically important DF ('Mild' and 'Moderate') was low and similar in both communities and considerably lower than the expected level at water fluoridation concentrations of 1 ppm. However, the prevalence of 'Very Mild' fluorosis was twice as frequent in Dublin than in Freiburg.