New Zealanders don't know enough about community water fluoridation, with one expert saying that is harming our decision-making.

A survey found a third of people do not know whether there are benefits to fluoridation - almost half don't know whether there are health risks.

Hawke's Bay District Health Board's director of oral health co-wrote the new research.

Dr Robin Whyman was happy to see that almost 58% of respondents believe there are dental benefits to fluoridating water supplies.

However, he said that with a third of those surveyed being unsure of the health benefits, the level of uncertainty "was higher than we had anticipated".

"It really points out to us that there is a need to really organise community consultations in a way that takes that into account."

He said local government often asks for public input on whether to fluoridate, through consultations or referendums.

"If that's going to work successfully then people need to understand what the benefits are from community water filtration, and have some level understanding of that, that they can translate into a decision."

Whyman said the research showed that Maori and Pacific respondents knew less about fluoride, and information needs to cater for that knowledge gap.