Fluoride is a natural substance. It 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.

Fluoride and its role in oral health

Fluoride works in 3 ways to help protect our teeth from decay:

  1. It makes teeth more resistant to decay by strengthening the tooth surface.
  2. It interferes with the growth of the bacteria which cause cavities.
  3. It helps to repair the early stages of tooth decay.

Eating and drinking increases the acidity in the mouth. This can remove the minerals from teeth, leading to tooth decay. The concentration of fluoride in saliva and plaque fluid is increased by:

  • drinking fluoridated water
  • brushing teeth with fluoride toothpaste.

Fluoride in water acts like a constant repair kit that:

  • neutralises the effect of acids that cause decay
  • helps to repair damage before it becomes permanent.

Fluoride toothpaste

Fluoride toothpaste is an effective method of reducing dental decay. It provides an additional benefit above that of fluoridated water.

Most fluoridated toothpastes on sale contain at least at least:

  • 0.221% sodium fluoride (1,000 ppm) , or
  • 0.76% sodium monofluorophosphate (1,000 ppm).

This is the recommended strength for adults and tamariki (children). These recommendations are based on years of research on the effectiveness of different toothpaste strengths.

Adults should use a pea-sized amount. Younger tamariki should use a half-pea sized amount of fluoride toothpaste on a small brush. Encourage your tamariki not to swallow or eat toothpaste. You should brush your teeth twice a day. 

Other sources of fluoride for oral health

Fluoride varnishes

Fluoride varnishes are professionally-applied, high-concentration varnishes used for people aged over 12 months and who are at high risk of developing dental decay. Speak to your oral health professional about this.

Fluoride mouth rinses

Fluoride mouth rinses may be used by people aged over 6 years and who are at high risk of developing dental decay. Speak to your oral health professional about this.

Fluoride gels and foams

Fluoride gels and foams are professionally-applied and may be appropriate in people over 6 years who are at high risk of dental decay. Speak to your oral health professional about this.

Fluoride tablets

Fluoride tablets are not recommended as a public health measure in Aotearoa New Zealand.

Community water fluoridation

Water fluoridation adjusts the natural level of fluoride in the water supply to between 0.7 mg per litre and 1.0 mg per litre. This is the optimal amount that provides protection against tooth decay. This is the range recommended by the World Health Organization.

Current fluoride levels in our untreated water supplies are not effective enough to help prevent tooth decay. Fluoride levels have been topped up in water supplies managed by many local authorities over several decades.

Water fluoridation is a proven public health measure to reduce tooth decay, in addition to:

  • brushing twice a day with fluoride toothpaste
  • eating healthy foods low in sugar
  • regular check-ups with a dental provider.

Over the last 60 years, many countries have examined the role of fluoride in water over the last 60 years.

This includes by the Office of the Prime Minister's Chief Science Advisor in Aotearoa New Zealand.

Fluoridation: An update on evidence — Office of the Prime Minister's Chief Science Advisor (external link)

Water fluoridation is endorsed by:

  • the World Health Organization
  • international health and science experts
  • national health and science experts.

Organisations in Aotearoa New Zealand that endorse community water fluoridation

Related websites

Ministry of Health - YouTube

Hear from trusted NZ health professionals and community leaders about community water fluoridation. They talk about the facts and the benefits of this critical health measure.

Ministry of Health

Information on community water fluoridation.

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