A ruling allowing South Taranaki District Council to fluoridate water could pave the way for councils looking to follow suit.
Anti-fluoride campaigners New Health lost their six-year battle in the Supreme Court in Wellington on Wednesday.
Water New Zealand chief executive John Pfahlert says it sets a precedent.
"They'll have much more confidence in making decisions about fluoridating public water supplies, knowing that their chances of a successful legal challenge are going to be pretty hard to overcome."
Last year, celebrity scientist Michelle Dickinson said it would take more than 7000 glasses of water to kill a person with fluoride - but they'd die of hyperdration long before that.
Mr Pfahlert says campaigners have cost the council a lot of time and money.
South Taranaki District Council added fluoride to the drinking water it supplies to the towns of Patea and Waverley in December 2012. The decision was made to improve poor dental health in the two towns and came after public consultation.
New Health has been ordered to pay the South Taranaki District Council $20,000 in reparation.
But Mr Pfahlert doubts it'll be the last we'll see of them.
"I think it reflects a move in society to not rely on scientific advice."