Manchester city water will remain fluoridated, after voters in Manchester and four surrounding towns overwhelmingly endorsed its continuation last night.

The five communities voted 10,455 in favor of fluoridation to 6,010 against, a tally of 63 to 37 percent.

The results was much stronger than in 1999, when Manchester voters adopted fluoridation by a mere 656-vote margin.

Yesterday’s referendum, however, incorporated the residents of four neighboring towns — Hooksett, Londonderry, Bedford and Goffstown. Some of the households in those towns receive water from Manchester Water Works.

“We tried to take the emotion out of the decision and base it on the scientific evidence. People made an educated decision and favored this in a landslide,” said Tom Dolan, a member of the Londonderry town council, which endorsed fluoridation.

In the days leading to the election, well-known medical experts in New Hampshire, including former U.S. Surgeon General C. Everett Koop, endorsed fluoridation.

“Overwhelmingly, the voice of the medical community was heard loud and clear,” said Manchester Mayor Robert Baines. “This says a lot about the voters. They listened to the facts and made a sound decision.”

Anti-fluoridation activist Barbara Hagan said the pro-fluoridation forces had “a hell of a lobbying machine.” Public health officials, dental societies and physician groups endorsed fluoridation, she pointed out.

They also took out ads, had posters in physician offices, sent out mailers and had signs on lawns. And several voters told Hagan their physicians had endorsed fluoridation, she said.

“People put a certain amount of trust in these individuals,” Hagan said. She attributed the wide margin to low voter turnout.

Five years ago, Manchester voters narrowly adopted fluoridation, the same year they elected Baines as mayor. However, opponents took the matter to court, successfully arguing that the vote disenfranchised water users in surrounding towns, who drank Manchester water but did not get a chance to vote on fluoridation.

The Supreme Court affirmed the decision, and the Legislature this year rewrote the law dealing with fluoride referenda and ordered yesterday’s vote.

Fluoridation opponents brought in experts, including John William Hirzy, a chemist who works for the Environmental Protection Agency, to speak against fluoridation.

And they raised issues with the chemical used by Manchester Water Works — hydrofluorisilicic acid — to fluoridate the water. The chemical contains minute amounts of arsenic and lead.

But fluoride supporters brought in their own expert: Koop. As they did five years ago, fluoridation supporters refused to debate opponents of fluoridation.

They said the procedure was safe and noted no adverse affects have occurred since the city started fluoridation. Health officials also stressed that Manchester water has been fluoridated for nearly four years.

“A lot of people are afraid of it, but my kids had it all their lives, and they’re fine,” said one-time New York resident Jim Oliver, a resident of Hooksett who is running for state representative.

Hagan hinted the fight may not be over. Two towns — Auburn and Derry — did not get a chance to vote. And she takes issue with the wording of the referendum.

“I still have a handful of cards,” she said.