The Hamilton City Council has voted to stop putting fluoride in its water supply.
The decision - criticised by doctors and dentists - came after the council held a three-day hearing last week with evidence from experts on both sides of the argument.
Councillors voted 7-1 on Wednesday to end fluoridation once supplies run out later in June, saving the council $48,000 a year. It had been using the chemical for 40 years.
The Waikato District Health Board says council's decision to stop fluoridating water supply is based on misinformation put forward by a vocal minority.
The board's medical officer of health, Felicity Dumble, says the decision goes against the mainstream opinion of most dentists and doctors in the city and believes residents' oral health will suffer.
Dr Dumble says anti-fluoride campaigners have created fear by making bizarre links between diseases and fluoride with no scientific basis. She says when fluoridation occurs there is a 10% drop in decay, but now it will rise again.
Deputy mayor Gordon Chesterman says although the anti-fluoridation campaigners were well-organised, they did not unduly influence the council's decision and there is an international momentum to remove fluoride from water supplies.
The Fluoride Action Network is delighted and says councils that still fluoridate should take note.
The move now means just 22 local councils out of 67 in New Zealand use fluoridation.