Mr Butterfield, of Timaru, said ''sadly'' the additive was taken out of his own city's water supply, and he did not want the same to happen in Dunedin.
A large number of submissions opposing fluoridation at this week's Dunedin City Council annual plan hearings prompted a request for staff to investigate the cost of holding a city-wide referendum as part of local body elections this year.
''In my view the scientific evidence is clear ... I don't believe the alternative arguments.
''I think that a referendum will expose uninformed views, but that's the Dunedin City Council's call,'' Mr Butterfield said.
Fluoridation was extremely beneficial to public health, and should be supported by local authorities, he said.
Mr Butterfield added he was not against public debate. Asked if the board's public health officials could do more to allay fears, he said: ''I don't know how you allay the concerns of a vociferous minority.''
Asked if there was particularly high concern about the additive in Dunedin, he said: ''I think it's something that manages to get stirred up all round the country, sadly.''
Fluoride Action Network NZ national co-ordinator Mary Byrne, of Wellington, said when contacted she believed a referendum would deliver an anti-fluoride verdict.
''Public opinion has swung against fluoridation,'' she said.
However, she believed a Dunedin referendum would draw a significant vote in favour of the additive, because those in fluoridated areas tended to assume it had reduced tooth decay, whereas this happened all over the country, regardless of which areas were fluoridated, she said.
She cited a study published last year in the journal Environmental Health Perspectives which suggested fluoride may adversely affect children's cognitive development.
The research was jointly carried out by Harvard School of Public Health and researchers in China.
