Fluoride is a natural substance that helps protect our teeth by making them stronger and by reducing tooth decay. It exists naturally in air, soil, fresh water, sea water, plants and in lots of food.
Fluoride is a natural substance that helps protect our teeth by making them stronger and reducing tooth decay. It exists naturally in air, soil, fresh water, sea water, plants and in lots of food.
The level of fluoride found in un-fluoridated water supplies in Aotearoa New Zealand is not enough to help prevent tooth decay, so topping up the fluoride levels in reticulated drinking-water supplies has been done in many regions for the last 60 years.
Extensive research carried out around the world, including in New Zealand, has established conclusively that community water fluoridation is safe, affordable and effective.
Read more about the safety, affordability and effectiveness of fluoride.
The Health (Fluoridation of Drinking Water) Amendment Act 2021 provides the Director-General of Health the ability to direct local authorities to add – or not to add – fluoride to their drinking-water supplies.
See more on this work:
Fluoride and its role in oral health
Fluoride works in three ways to help protect our teeth from decay:
- Fluoride makes teeth more resistant to decay by strengthening the tooth surface
- Fluoride interferes with the growth of the bacteria which cause cavities
- Fluoride helps to repair the early stages of tooth decay.
Eating and drinking increases the acidity in the mouth, which can remove the minerals from teeth and lead to tooth decay. Drinking fluoridated water and brushing teeth with fluoride toothpaste increases the concentration of fluoride in saliva and plaque fluid. Fluoride in water acts like a constant repair kit that neutralises the effect of acids that cause decay and helps to repair damage before it becomes permanent.
Fluoride toothpaste is an effective method of reducing dental decay. It provides an additional benefit above that of fluoridated water.
Based on the consensus of many years of research on the effectiveness of different strengths of toothpaste, the New Zealand Guidelines Group recommends that adults and children brush their teeth twice daily with toothpaste containing at least 1,000 ppm of fluoride (0.221% sodium fluoride or 0.76% sodium monofluorophosphate). Adults should us a ‘pea’ sized amount and younger children should use just a half pea sized amount of the same strength toothpaste on a small brush. Children should be discouraged from swallowing or eating toothpaste due to the possible risk of dental fluorosis.
Read the New Zealand Guidelines Group’s Guidance on the use of fluoride.
Despite widespread use of fluoride toothpaste and public provision of dental services for children, tooth decay is still the single most common chronic disease for New Zealanders. That’s why water fluoridation is recommended by key public health agencies around the world as an important contribution to oral health.
Water fluoridation is the process of adjusting the natural level of fluoride in the water supply to between 0.7 and 1.0 parts per million (ppm). This is the optimal amount recommended by the World Health Organization to provide protection against tooth decay.
New Zealand's most recent national oral health survey shows on average 40% less tooth decay experience for children in fluoridated areas than in those areas without it, while the Australian National Survey of Adult Oral Health (2013) showed that adults experience 20–30% less tooth decay. The benefits of fluoridation are greater for Māori, Pacific peoples, children, and communities with worse oral health outcomes.
For further information, see Fluoride – Safe, Effective and Affordable.
Other ways to increase fluoride levels
Fluoride tablets are not considered suitable as a public health measure because of the possible risk of fluorosis, especially in children. However, oral health professionals may still recommend fluoride tablets to individuals on a case-by-case basis.
Fluoride mouth rinse may be used by people aged 6 years and over who are at high risk of developing cavities as part of a preventative oral health plan. After rinsing, mouth rinse should be spat out and not swallowed.
Fluoride gels, foams and varnishes may be applied by an oral health professional or other health practitioner, they are suitable only for people who are at high risk of dental carries.
In addition, in some European countries it is not practical to add fluoride to the water supply, which means that alternative methods are used to boost fluoride to optimal health levels – such as adding fluoride to salt or milk.
For further information, see the New Zealand Guidelines Group’s Guidance on the use of fluoride.