Study of 12-year olds in north of England finds water fluoridation narrows the dental caries divide between rich and poor

A study (Journal of Dentistry, 2000) comparing oral health and social deprivation among nearly 7,000 twelve-year olds in the north of England found that water fluoridation had markedly reduced 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 1992/3 and in fluoridated Newcastle upon Tyne and non-fluoridated Liverpool.

When areas within the study with national average levels of social deprivation were compared, on average those supplied with fluoridated water had a 37% lower rate of decayed, missing and filled teeth for 12-year olds than areas supplied with non-fluoridated water.

When very deprived areas were compared, on average those in fluoridated Newcastle had a 52% lower rate of tooth decay than those in non-fluoridated Liverpool.

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 found that in non-fluoridated electoral wards children from the most deprived backgrounds had around 100% more decayed, missing and filled teeth than children from the most affluent backgrounds.

In fluoridated electoral wards, children from the most deprived backgrounds had only about 50% more teeth affected by decay than those from the most affluent backgrounds.  In other words, the dental health divide between social classes in Newcastle had been halved by comparison with the gap in Liverpool.

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: “The result from this study reaffirms the effectiveness of water fluoridation as the primary preventive measure capable of bridging the ‘dental health gap’ by differentially improving the dental health of those who are socio-economically deprived.”

1. Jones CM, Worthington H (2000). Water fluoridation, poverty and tooth decay in 12-year old children. Journal of Dentistry, 28, 389-393.

QUOTES FROM STUDY OF
12-YEAR OLDS
Dental health divide would become narrower with fluoridation

“Even if water fluoridation was introduced there would still be a social class gradient in disease levels, though unlike many health promotion initiatives, on the evidence from this study, the ‘dental’ health divide would become narrower.”

Benefits over and above those achieved from fluoride toothpaste

“Fluoride toothpaste is suggested as an alternative to water fluoridation for those who choose to use it.  However, almost all of the toothpaste sold in the UK contains fluoride and we can safely assume that despite almost universal fluoride toothpaste usage, water fluoridation still produced a 37% reduction in decay levels in 12-year-old children at an electoral ward score of zero.”

Effectiveness of water fluoridation in bridging dental health gap

“The result from this study reaffirms the effectiveness of water fluoridation as the primary preventive measure capable of bridging the ‘dental health gap’ by differentially improving the dental health of those who are socio-economically

deprived.”