Adding fluoride to water supplies.
This is such a contentious subjects. The observation that towns in the North East of England which were close together had different teeth decay levels lead to the observation that the fluoride content of the drinking water was the determinant.
The next step was to fortify the drinking water of fluoride deficient water. ( Germany, Ireland, Portugal, Spain, UK and USA) or table salt ( France ). Water fluoridation is intended to reduce social inequality in the provision of fluoride.
There has been much debate on this subject which has generated heat and dismay. Is this mass medication or acting within commonly found natural limits. If a medicine then the standard of proof has to be that of a medicine.
In the BMJ this topic has been reviewed
Cheng, Chalmers, Sheldon ( 2007 ) Adding fluoride to water supplies BMJ vol 335, 699-702
A review commissioned by the Department of Health in England at the University of York looked at the evidence for benefit of adding fluoride to drinking water on dental health. Whilst there are many papers on this subject many did not meet proper scientific standards.
A problem is fluorosis, teeth mottling which was visible in 48% and aesthetically concerning in 12% of people studied at 1 part per million.
A claim for an increase in bladder cancer from Taiwan proved to be a difficult one to prove or disprove and the evidence is at the best marginal.
Studies become more difficult because of the wide availability of fluoride containing toothpastes. The benefit in young children appears to be 24%.
Fluoride is the main factor that alters the resistance of teeth to acid attack and sugar in plaques. Caries are reduced fluoride which
Reduces and inhibits the dissolution of enamel
Alters the ecology of the plaque.
Fluoride is most effective when used topically
- Martin Eastwood