Fluoride is a natural mineral found throughout the earth's crust and widely distributed in nature. Some foods and water supplies contain fluoride.
Fluoride is often added to drinking water to help reduce tooth decay. In the 1930s, researchers found that people who grew up drinking naturally fluoridated water had up to two-thirds fewer cavities than people living in areas without fluoridated water. Studies since then have repeatedly shown that when fluoride is added to a community's water supply, tooth decay decreases. The Australian Dental Association and the World Health Organisation, among many other organisations, have endorsed the use of fluoride in water supplies because of its effect on tooth decay.
How does fluoride work?
Fluoride helps prevent cavities in two different ways:
- Fluoride concentrates in the growing bones and developing teeth of children, helping to harden the enamel on baby and adult teeth before they emerge.
- Fluoride helps to harden the enamel on adult teeth that have already emerged.
Fluoride works during the demineralisation and remineralisation processes that naturally occur in your mouth.
- After you eat, your saliva contains acids that cause demineralisation, a dissolving of the calcium and phosphate that make up tooth enamel and dentine.
- At other times when your saliva is less acidic it does just the opposite, replenishing the calcium and phosphate that keep your teeth hard. This process is caused remineralisation. When fluoride is present during remineralisation, the minerals deposited are harder than they would otherwise be, helping to strengthen your teeth and prevent dissolution during the next demineralisation phase.
How do I know if I am getting enough fluoride?
If your drinking water is fluoridated, then brushing regularly with fluoride toothpaste is considered sufficient for adults and children with healthy teeth at low risk of decay.
If your community's water is not fluoridated and does not have enough natural fluoride in it (1 part per million is considered optimal), then your dentist may advise you of other ways you can improve fluoride exposure. Your dentist can tell you how much fluoride is right for your family, so be sure to ask for his or her advice.
If your water comes from a public water supply, you can find out if it is fluoridated by calling your local water district. If your water comes from a private well, you can have it analysed by an independent environmental testing company that provides water-testing services.