Study of five-year olds in north of England finds water fluoridation narrows the dental caries divide between rich and poor

A study (British Dental Journal, 1999) comparing oral health and social deprivation among 10,000 five-year olds in the north of England found that water fluoridation had virtually halved tooth decay overall and, at the same time, had reduced the ‘dental caries divide’ ordinarily separating children from the most affluent and poorest backgrounds (1).

Researchers looked at the numbers of decayed, missing and filled teeth recorded at electoral ward level in surveys of children’s teeth carried out in 1991/2 and 1993/4 in fluoridated Newcastle upon Tyne and North Tyneside, non-fluoridated Salford and Trafford, and naturally fluoridated Hartlepool.

When areas within the study with national average levels of social deprivation were compared, on average those supplied with fluoridated water at a concentration of 1 part of fluoride per million parts of water (1 ppm) had a 43% lower rate of decayed, missing and filled teeth for five-year olds than areas supplied with non-fluoridated water.

Importantly, the study also found that the differences in dental health between children from affluent and deprived backgrounds in fluoridated areas were smaller than the differences in non-fluoridated areas.

Using Townsend deprivation scores from the 1991 national census, the study identified a fourfold difference in average rates of decayed, missing and filled teeth between children from the most affluent and deprived backgrounds in non-fluoridated electoral wards.

By comparison, there was only a two-fold difference in fluoridated electoral wards, and an even lower difference in naturally fluoridated Hartlepool, where the average fluoride concentration in water was 1.2 ppm (higher than the target level recommended for community water fluoridation schemes in England).

As the authors of the study acknowledge, water fluoridation does not eradicate the dental health gap between rich and poor.  However, it reduces the gap that is otherwise found in non-fluoridated areas.  It does this because it most benefits children in areas with the highest levels of tooth decay, which tend to be those with the highest levels of social deprivation.

They conclude in their report that there is ‘an urgent necessity’ to introduce water fluoridation as the ‘most cost-effective preventive measure capable of bridging the dental caries gap’.

1. Jones CM, Worthington H (1999). The relationship between water fluoridation and socio-economic deprivation on tooth decay in 5-year old children. British Dental Journal, 186, 397-4000.

Evidence-based and effective

“The dental profession can advocate water fluoridation, secure in the knowledge that it is evidence-based and effective. Our results clearly show that today we have almost twice as much tooth decay in non-fluoridated areas because the population is denied water fluoridation.”

Study found 43% reduction in decay in the fluoridated area – despite use of fluoride toothpaste in both areas

“Almost all of the toothpaste sold in the UK contains fluoride and we can safely assume there was no difference in the proportion of toothpaste used….Despite fluoridated toothpaste, water fluoridation still produced a 43% reduction in decay.”

Most beneficial to more deprived children

“There is much supporting literature for the finding that water fluoridation is differentially beneficial to more deprived groups.”