The effect of water fluoridation and social inequalities on dental caries in 5-year-old children

Background Many studies have shown that water fluoridation dramatically red uces dental caries, but the effect that water fluoridation has upon reducin g dental health inequalities is less clear. The aim of this study is to des cribe the effect that water fluoridation has upon the association between m aterial deprivation and dental caries experience in 5-year-old children. Methods It is an ecological descriptive study of dental caries experience u sing previously obtained data from the British Association for the Study of Community Dentistry's biennial surveys of 5-year-old children. This study examined the following data from seven fluoridated districts and seven comp arable non-fluoridated districts in England: 1) dental caries experience using the dmft (decayed, missing, filled teeth) index; 2) the Townsend Deprivation Index of the electoral ward in which the child lived; 3) whether fluoride was present at an optimal concentration in the drinking water or not. Results A statistically significant interaction was observed between materi al deprivation (measured by the Townsend Deprivation Index) and water fluor idation (P < 0.001). This means that the social class gradient between mate rial deprivation and dental caries experience is much flatter in fluoridate d areas. Conclusion Water fluoridation reduces dental caries experience more in mate rially deprived wards than in affluent wards and the introduction of water fluoridation would substantially reduce inequalities in dental health.