The Hamilton City Council’s leaflet to ratepayers about its decision to ban fluoride in their town water supply gives oral health information that is wrong, unscientific and misleading to Hamilton people, leading NZ dental authorities say.

Dr Jonathan Broadbent, a public health dentistry specialist and researcher from the University of Otago’s Faculty of Dentistry – New Zealand’s only dental training school – says the largely inaccurate oral health care advice given out by the Hamilton City Council (HCC) in its recently-released leaflet should be corrected and residents should be advised to disregard it.

The leaflet appeared to have been over-simplified to the point where it did not reflect true and accepted public health advice, or the changed circumstance of Hamilton water now being “fluoride free.”

“I suggest they have a public communication problem on their hands and need to act quickly to put the correct information out there; or seek help from those that really are in the business of producing health advice that the public can rely on,” he says.

The New Zealand Dental Association says the Council made a poor decision when it removed the health benefit of water fluoridation.

“It is not an authority on dental public health and is giving advice well outside its remit as a civic authority,” says Dr Geoff Lingard, President of the Dental Association.

Dr Broadbent says the leaflet is incorrect on several important public health fronts. It was wrong to indicate, as the one-page leaflet did, that low-fluoride toothpaste was best for children’s teeth when the New Zealand Guidelines for the Use of Fluorides state that “toothpaste of at least 1000 parts per million is recommended for all ages.” That measurement reflected standard fluoride toothpaste, not low fluoride toothpaste.

The HCC leaflet also suggested a “pea-sized” amount of toothpaste be used for all ages, and did not clarify that, as the NZ guidelines suggest “a smear of fluoride toothpaste is recommended until five years of age. From age 6 years, a pea-sized amount can be used.”

“For children aged under 6 years living in fluoridated areas who are at low risk of tooth decay, fluoride toothpaste less than 1000 parts per million may be used if parents wish, but contrary to what was suggested in the leaflet, parents in Hamilton shouldn’t be encouraged to use low fluoride toothpaste for their children whatever the age, since Hamilton is now un-fluoridated, says Dr Broadbent.

“When Hamilton was fluoridated, parents could have chosen to do so, but it isn’t recommended now. Families should purchase toothpastes that contain at least 1000 ppm fluoride and avoid those labelled ‘fluoride free’, ‘child strength’ or ‘low fluoride’,” he says.

The HCC leaflet’s claim that “applications by means that directly affect the tooth surface are more effective than fluoridation” is also misleading.

“This is misleading because fluoridated water also acts on the tooth surfaces by direct topical action. Each time we eat food and drinks prepared with fluoridated water, fluoride concentrations in the mouth remain elevated, so the teeth benefit both during and after eating. Water fluoridation works,” he says.

Dr Broadbent says it is also concerning to see HCC provide a link to their own webpage regarding a health issue, rather than to the webpage of a health authority.

For more information on fluoride, people should be directed to the NZ Dental Association’s ‘Healthy Smiles’ website (,283,, the Ministry of Health’s statements on fluoride ( or, or to the website of the National Fluoridation Information Service (

Dr Lingard believes the HCC should not be directing Hamiltonians to their own webpage for information. Many of the tribunal submissions available on their site contain “seriously erroneous” information.