Dental benefits of adding fluoride to water may have declined, study finds

Using fluoride in drinking water to improve dental health may be less effective now than it was in the past, according to a new major review.

Ten per cent of people in England have fluoride added to their drinking water by the council and the government is considering expanding the reach of fluoridation projects.

But a new study found the benefits of fluoridating water seem to have declined since fluoride toothpaste became widely available in the 1970s.

Academics at Manchester, Dundee and Aberdeen universities compared 157 studies looking at the effect of fluoridation on the dental health of communities.

When the government began adding fluoride to drinking water, it reduced the number of decayed, missing or filled teeth by two whole teeth on average among children with their baby teeth, researchers said.

However, once fluoride toothpaste became widely available, that number declined.

Now, it is equivalent to a reduction of a "quarter of a tooth" that is decayed, missing or filled, on average.

Fluoride is still added to water mainly in the West Midlands and the North East.

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The government is currently deciding whether to extend that to cover Darlington, Durham, Gateshead, Hartlepool, Middlesbrough, Newcastle, Northumberland, North Tyneside, Redcar and Cleveland, South Tyneside, Stockton and Sunderland.

"Water fluoridation is only having a modest benefit on dental caries, and those benefits may take years to be realised," said University of Manchester's Professor Anne-Marie Glenny, who co-authored the paper.

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Professor Glenny said water fluoridation should be part of a "comprehensive programme of public health interventions, including those that reduce sugar consumption or other preventative measures".