Oral health expert Robin Whyman slams claims made by fluoride critic Paul Connett

DHB clinical director for oral health Dr Robin Whyman says evidence shows fluoride can help reduce dental decay. Photo / File

Fluoridating drinking water is about protecting the health interests of the wider population, a dental expert says.

This comes in response to a Fluoride Free meeting held on Wednesday, where prominent critic Dr Paul Connett told a 100-person audience about water fluoridation and the harm he argued it posed to health and the environment.

However, Hawke's Bay District Health Board clinical director for oral health Dr Robin Whyman said the board supported fluoridation as evidence showed its effect on reducing dental decay, particularly in children.

"We think it's good for our community, and we think it has a positive health benefit which will reduce peoples need for treatment ... and reduce cost both to the DHB and to people's pockets."

Their position was consistent with that of the Ministry of Health, and other DHBs around the country. It was based on research which had been repeatedly backed up in both national and international studies, he said.

The Wednesday meeting was part of a New Zealand speaking tour featuring Dr Connett, a retired professor of environmental chemistry and toxicology at St Lawrence University, as the guest of Fluoride Free NZ.

His presentation touched on a number of arguments, including that fluoridation was a reckless medical practice, and that the widespread addition of the chemical was "unethical" as the normal distribution response people had to any substance meant only some would be helped while others could face harm.

In response, Dr Whyman said this argument had been rejected many times as the concentration of fluoridation used in the water supply was not enough to register as "medicinal".

"The question turns on whether I want this done for me versus the wider interests of the whole population's health. This is a population, or public health measure, it's alongside the same things as we iodise our salt, we put folate in bread.

"We take those measures in the interest of the wider population's health."

Currently Hastings is the only district in the Hawke's Bay area with a fluoridated water supply. Central Hawke's Bay had one fluoridated water supply until 2012.

Dr Whyman said they had found 57 per cent of Maori 5-year-olds living in CHB were decay free at the end of 2013, which had dropped to 24 per cent at the end of 2016.

"We feel very strongly that there is a benefit we need to take advantage of as a community."

This comes as a controversial bill is before Parliament which would give district health boards the power to make decisions about water fluoridation - rather than local authorities.