Results come as group pushes to have chemical removed from Auckland supply.
Almost half of New Zealanders support the adding of fluoride to their drinking water despite councils increasingly dumping it, a Herald-DigiPoll survey shows.
The poll showed 48 per cent of New Zealanders supported the addition of fluoride - double the 25 per cent of those who opposed its use. A further 24 per cent believed the issue should be left to local councillors to decide.
The results come as the spotlight on fluoride moves to Auckland, where an anti-fluoridation group is lobbying to have it removed from the city's drinking water supply after Hamilton last month decided to stop fluoridating its water.
Fluoride Action Network New Zealand held a meeting in Freemans Bay to gather support for its campaign. National co-ordinator Mary Byrne said it was the first in a series of meetings around the region designed to change people's thinking.
Ms Byrne said the DigiPoll results were encouraging, particularly after a poll of Hamilton residents in 2006 showed 70 per cent (of the 38 per cent who voted) were in favour of fluoridation.
"I think it shows we are having a big change of opinion in New Zealand ... It's a huge swing in what people know about fluoride now," she said.
The network had made submissions against fluoridation during hearings on the city's Auckland Plan but Ms Byrne was doubtful the council would hold a tribunal until after this year's local body elections.
The Auckland Council is to prepare a water strategy action plan that will look at a range of issues relating to the region's water supply over the next 20 to 30 years.
Ms Byrne said the group had science to back its claims that fluoride was toxic and harmful when added to water and without applying it directly to teeth offered none of the benefits health authorities claimed.
However, that is hotly disputed within the science community.
The network claims fluoridation is mass medication that can be harmful to pregnant women and toddlers and is linked to a range of illnesses from arthritis to cancer.
A majority of Auckland councillors told the Herald on Sunday they supported the ongoing fluoridation of the city's water supply.
The council's chairman of the environment and sustainability forum, Wayne Walker, said yesterday that he left the meeting with a level of concern after listening to several "very credible" speakers.
"We need to look at the issue scientifically and objectively and remove the politics from our decision-making," he said.
Waitakere councillor Sandra Coney saw no reason to change things.
"As far as I can see the only negative impact of fluoridation is for a small number of people who might get fluorosis [discolouration of the teeth] but it doesn't seem to happen to any great level. All the other things that are claimed have not been proven."
Meanwhile, Hamilton City councillor Ewan Wilson is ramping up his efforts to overturn a tribunal decision that ended fluoridation in Hamilton last month.
The council will debate a city-wide fluoride referendum this Thursday.