Lawyer Duncan Laing, who acted for South Taranaki District Council, says it could set a precedent for other local authorities considering fluoridation, or considering to stop fluoridation.
"It will certainly be persuasive if there is another High Court case," Mr Laing said.
"[The case] raised and clarified a number of issues, including the council's power to fluoridate water.
"There has been really very little case authority on some of these issues, in terms of the Bill of Rights Act, so it's quite an important case in terms of what councils can do, whether they've got the power to do it, and what the implications to the Bill of Rights are too.
"It's a very clear decision and will be interesting to see how it's received."
The issue of fluoridation of council water supplies has been a hotly-debated topic across New Zealand in recent years.
Hamilton City Council decided to stop adding fluoride to the civic water supply on June 21 last year.
The council made a poor decision when it removed the health benefit of water fluoridation, the New Zealand Dental Association said.
Dr Jonathan Broadbent, Public Health Dentistry Specialist at the University of Otago, today welcomed the High Court decision to reject opposition to councils to fluoridate drinking water.
"This decision reaffirms the legal basis of the scientifically sound practice of community water fluoridation," he said.
"The people of New Zealand have the right to benefit from this effective public health practice. Community water fluoridation benefits everyone, especially those New Zealanders who are disadvantaged."
Prof Murray Thompson, Dental Epidemiology and Public Health, University of Otago, added it was a "sensible" judgment, affirming the important role of community water fluoridation in keeping New Zealanders healthy.
Nearly 70 per cent of Hamilton voters voted for fluoride in last year's Hamilton City Council referendum, the Waikato District Health Board said in a statement today.
DHB chief executive Craig Climo said there were now no excuses, and Hamilton City Council should put fluoride back in the city's water supply.
"Community water fluoridation is one of the very few health interventions where the beneficiary of the service actually doesn't need to do anything to enjoy the benefits," he said.
"It comes at a very low cost and is of very clear health benefit. We shouldn't lose those sorts of opportunities."