Changes in dental fluorosis following the cessation of water fluoridation

To determine changes in the prevalence of dental fluorosis, and in perceptions of aesthetic concerns due to dental fluorosis after water fluoridation ceased.

Schoolchildren in second and third grades were examined in 1993-94, 1996-97 and 2002-03 to determine changes in the prevalence of dental fluorosis following fluoridation cessation of the public water supplies in 1992. The Thylstrup-Fejerskov Index (TFI) was used to quantify dental fluorosis. Perceptions of aesthetics were assessed by questionnaires which were sent home to parents. Residence and dental histories were confirmed on all children to determine the extent of exposure to all types of fluorides. Comparisons between the three surveys were used to establish the influence of fluoridated water and other fluoride sources on the occurrence and severity of dental fluorosis. Aesthetic ratings from parents were used to assess the aesthetic conditions of maxillary anterior teeth across the three surveys.

When fluoride was removed from the water supply in 1992, the prevalence and severity of TFI scores decreased significantly from the 1993-94 survey cycle when compared with the 1996-97 and 2002-03 survey cycles. The use of fluoride supplements and fluoride dentifrice also decreased during this study period. Analyses were unable to determine the influence of these different fluoride exposures on the changes in TFI scores over time. Comparisons of aesthetic ratings from parents between survey cycles failed to show any significant differences.