Councils are divided over the Ministry of Health's directive to add fluoride to drinking water.
Fourteen local authorities on Wednesday were ordered by Director-General of Health Ashley Bloomfield to start fluoridating drinking water supplies in a bid to cut tooth decay, especially among children, Māori and Pasifika.
Rotorua doesn't yet have fluoridated water and Mayor Steve Chadwick is glad the Ministry of Health has finally pushed the initiative.
"I think it's long overdue, myself," she told AM. "It's a bold decision.
"We've got appalling levels of tooth decay here… so I do believe, as a previous Associate Health Minister, this is the right thing to do and the decision was made by the right authority."
But, appearing on AM alongside Chadwick, Far North District Mayor John Carter wasn't happy.
"The problem is there's been consultation at all."
Ratepayers potentially having to step up and fund the fluoridation also worried him, Carter said.
He wanted more analysis of the benefits of fluoridation - something he said the council couldn't currently advise his community on.
"We can't go out to the community and say, 'We need to do this because this is going to be the advantage to you,'" Carter said.
The 2009 New Zealand oral health survey showed children living in fluoridated water areas had a 40 percent lower lifetime prevalence of tooth decay.
Philip Schulter, the head of the University of Canterbury's school of health sciences, told Newshub Late the research on fluoride was compelling and the evidence of its effectiveness was overwhelming.
"It was actually labelled as one of the public health successes by the CDC (US Centers for Disease Control and Prevention) which is a large, important body based in America," Prof Schulter said on Wednesday.
"We have done some work recently, in a national study, where we actually demonstrated, even in today's world... community water fluoridation still makes a massive difference."
A comprehensive review of the health effects of water fluoridation in New Zealand, published in 2014 and examined by the Prime Minister's chief science advisor, found "there were no adverse effects of fluoride of any significance arising from fluoridation at the levels used in Aotearoa New Zealand".
Carter, meanwhile, believed the issue was a local Government one - not central.
"It's just typical again of the Government… all the changes and not consulting with our local people," Carter said. "It's really frustrating."
Dr Bloomfield said on Wednesday Māori, Pasifika and New Zealand's most vulnerable would particularly benefit from community water fluoridation.
"Water fluoridation helps prevent tooth decay, along with brushing your teeth twice a day with fluoride toothpaste, eating healthy food and avoiding sugary drinks," he said in a statement. "Fluoride in water acts like a constant repair kit for your teeth.
"Fluoridated water is safe for everyone to drink - including babies and the elderly - and fluoride exists naturally in air, soil, freshwater, seawater, plants and food."
