But Whangarei dentist Lawrie Brett said his opinion was that fluoridation would not bring the benefits claimed by the Government and sugar was a far greater danger to youngsters' teeth.
Dr Brett said there was plenty of scientific research that showed fluoride was a toxin and he did not believe fluoridation would help reduce dental decay.
"The Ministry of Health has statistics that show in areas where fluoridation was removed from drinking water the dental health of children in those areas actually improved after the fluoride was removed.
From Timaru in 1975, Ashburton in 2002 and New Plymouth in 2010, all those places stopped fluoridation and saw dental health improve afterwards," he said.
"Those are the Ministry of Health's statistics so it has to be explained: Why the big rush to force fluoridation on people when they don't want it?"
Dr Brett said NDHB had campaigned for years to fluoridate the region's water supplies and he thought it was a fait accompli that public supplies would be fluoridated.
"A referendum would just give the result the Government wanted as the pro-fluoride lobby would have millions of Government funding to push their case but the opponents wouldn't have that financial backing to get their messages out," he said.
"There's very strong evidence that has come out just last year from Harvard University that links fluoride with ADHD, and from Kent University that says there's a possible relationship with hypothyroidism.
"That's the latest research from two of the top universities and hyperthyroidism leads to obesity, high blood pressure, heart problems and depression - all big issues already in Northland."
NDHB principal dental officer and oral health adviser Neil Croucher said the DHB was upbeat about the announcement and said from a scientific, evidence-based perspective fluoride was safe and effective in reducing tooth decay.
"There's no doubt that children living in areas with fluoridated water supplies in New Zealand have better dental health than those living in unfluoridated areas," Dr Croucher said.
NDHB had been campaigning for years to get Northland's public water supplies fluoridated, and he said a DHB could provide information to the public and councils that would explain the benefits and help them "see the wood from the trees" through the "misinformation" that had been spread about fluoride.
Dr Croucher said any decision would be made through consultation with the public.
He said on average in 2013, every 5-year-old in Northland had an average of 3.64 teeth decayed, missing or filled, while those in Auckland living in a fluoridated area had an average of 1.77 decayed, missing or filled teeth.
"So on average in 2013, a 5-year-old child in the Northern region living in a fluoridated area has roughly half the number of decayed, missing and filled teeth than a 5-year-old child living in Northland. Some of this difference would be directly related to Northland children not having access to the preventive benefits of water fluoridation," Dr Croucher said.