Access to fluoridated drinking-water

This indicator presents information about the population with access to fluoridated drinking water in Aotearoa New Zealand.

Background information

Tooth decay (dental caries) is a major chronic disease among New Zealanders of all ages. It is often accompanied by pain, infection, and tooth loss, and can lead to absence from work or school (OPMCSA). Dental caries (cavities) are caused by acids that are produced by bacteria in the mouth. The acids dissolve the hard enamel of the tooth surface and start dental decay. A high-sugar diet can raise the number of bacteria, which in turn increases the production of decay-causing acids (Ministry of Health 2010; OPMCSA).

Fluoride is known to protect teeth against dental caries, so adding fluoride to drinking water supplies can help limit tooth decay. Fluoride works to protect teeth in three ways (OPMCSA 2021):

• strengthening of tooth enamel, making teeth more resistant to decay
• interference with the growth of bacteria that cause cavities
• repair of the early stages of tooth decay.

Information about this indicator

The datasets for this indicator come from the Ministry of Health’s ‘Annual report on drinking-water quality’ (prior to 2024) and Taumata Arowai's 'Public Register of Drinking Water Supplies'.

References

1. Ministry of Health. 2022. Annual report on drinking water quality 2020-2021. Wellington: Ministry of Health.

2. Office of the Prime Minister’s Chief Science Advisor (OPMSCA). 2021. Fluoridation: an update on evidence. Wellington: Office of the Prime Minister’s Chief Science Advisor.

3. Taumata Arowai. 2024. Extract from the public register of drinking water supplies. Wellington: Taumata Arowai (Personal communication with Taumata Arowai analysts)