Most water supplies contain some fluoride naturally (it’s the thirteenth most abundant element in the earth’s crust). Fluoridation is the process of topping up the natural fluoride content of the public water supply to a level high enough to improve dental health. It’s been done, here and overseas, for more than 50 years — long enough to provide reliable information about the benefits (and the risks).
Evidence from the UK
In 2000, a group of 10 experts (commissioned by the UK National Health Service) conducted a systematic review of the entire body of scientific evidence on public water fluoridation available at the time. Though they found much of the research lacked rigour, they found the evidence strong enough to conclude that:
- Fluoridation of drinking water really does reduce the prevalence of decayed teeth, increasing the percentage of children totally free from tooth decay by about 15%.
- Fluoride in drinking water provides an additional benefit over and above that derived from fluoride in toothpaste and topical applications provided by dentists.
Further investigation by the UK Department of Health confirmed these findings, examined additional research and highlighted the benefits of fluoridation for adults as well as children. This second report (published in 2002) found evidence that:
- In general, more adults are keeping more of their own teeth into old age, and having less trouble with them, where there’s fluoride in the drinking water.
- Fluoridation also confers additional benefits such as reductions in the number of people suffering from toothache or requiring general anaesthesia for dental treatment.
Many Australian cities have added fluoride to the water since the 1970s, so millions of people have now been supplied with drinking water containing fluoride at the recommended levels for long enough for the benefits to be clearly evaluated from health statistics.
The National Health and Medical Research Council (NHMRC) reviewed the evidence in 1999 and concluded that, “Water fluoridation at optimal levels, varying from 0.6 ppm in subtropical regions to 1.1 in temperate climates, continues to provide significant benefits in the prevention of dental caries for both deciduous [baby] and permanent teeth. The evidence for a protective effect on dental health is strongest in childhood but can also be demonstrated in adults.” (‘ppm’ means parts per million — 1 ppm would be equivalent to 2 kg of fluoride in an Olympic pool containing two million litres of water.)
These conclusions are supported by more recent research:
In NSW, a major 2005 study that examined the dental records of nearly a quarter of a million schoolchildren aged 3–15 found that those living in areas with fluoridated water were significantly less likely to have decayed, missing or filled teeth than children living in areas without added fluoride in the drinking water.
Another 2005 study of 973 Australian army recruits showed that those with no exposure to water fluoridation had 40% more filled, missing or decayed teeth than recruits who had grown up with fluoridation.
What about toothpaste?
Most toothpaste contains fluoride. Clinical trials have shown that while fluoride toothpaste definitely helps prevent tooth decay, it isn’t as effective a public health program as fluoridated drinking water, which provides significant benefits for children and adults over and above those from fluoride toothpaste.
And fluoride toothpaste isn’t suitable for small children because there’s a risk that they’ll swallow too much of it and develop dental fluorosis (see Fluoride’s downside). Experts recommend that:
- You don’t use any toothpaste when cleaning very small children’s teeth (up to the age of about 18 months).
- Children aged between 18 months and five years should use low-fluoride toothpaste (0.04–0.05% fluoride). They should clean their teeth twice a day with adult supervision, use only a pea-sized amount of toothpaste and be taught to spit it out and not swallow.
- Kids aged six or more should clean their teeth with standard fluoride toothpaste at least twice a day, and not swallow.
If you live in an area without fluoridated water your kids might need to start using fluoride toothpaste earlier — check with your dentist.