The effect of water fluoridation and social deprivation on tooth decay

Abstract

We examined the effect of both artificial and natural water fluoridation on tooth decay in 5-year-olds, after controlling for deprivation by the use of the Jarman Under Privileged Area score.Five-year-old children (n= 10,004) in electoral wards in three areas—naturally fluoridated Hartlepool, fluoridated Newcastle & North Tyneside and non-fluoridated Salford & Trafford—were dentally examined and statistically significant, positive correlations were demonstrated regardless of the level of water fluoridation between deprivation and tooth decay. Weighted multiple linear regression showed a statistically significant interaction between ward Jarman score, mean tooth decay and both types of water fluoridation, confirming that in more deprived areas there is a statistically greater reduction in tooth decay.At a Jarman score of zero (the English average) there was a predicted 44% reduction in decay in 5-year-olds in fluoridated areas, increasing to a 54% reduction in wards with a Jarman score of 40. In an area with natural fluoridation at a level of 1.2ppm the reduction was 66%, increasing to 74% in electoral wards with a Jarman score of 40.Tooth decay is associated with social deprivation and water fluoridation is more efficacious in deprived areas at an electoral ward level. The findings confirm that the implementation of water fluoridation, especially in areas of social deprivation, has been effective in halving tooth decay in 5-year-old children.