CUMBERLAND — Cumberland voters overwhelmingly approved yesterday a bid to lift the city’s decade-old ban on fluoridating its water supply, signaling a major shift in Western Maryland’s traditional hostility to the widely accepted cavity-fighting chemical. By a vote of 2,525 to 1,633 in unofficial returns, residents opted to repeal a charter provision barring the addition of fluoride or any other “substance” to the city’s drinking water.

Thirty-three percent of the city’s voters cast ballots in the referendum, which was voted on with a general election for mayor and City Council of the economically struggling Allegany County seat.

Lee Fiedler, retired chief executive of the now-defunct Kelly- Springfield Tire Co., easily outpolled self-employed contractor Ronald Hampton for mayor in the race to replace retiring eight-year incumbent Edward Athey. Fluoridation was not a major issue in the mayoral or council races, however, because most candidates — including Fiedler — said they would be guided by the outcome of the referendum.

Dr. William C. Tompkins, president of the Allegany/Garrett Dental Society and a leader of the pro-fluoride campaign, expressed pleasure at the outcome, which occurred despite opposition by the vocal anti- fluoride Pure Water Committee.

“Really, the voters of Cumberland showed some courage today,” Tompkins said. He said he expects the newly elected mayor and council to follow through with fluoridating the community’s water.

M. Virginia Rosenbaum, president of the Pure Water Committee, blamed low voter turnout for her group’s defeat but vowed to continue to resist efforts to fluoridate the city’s water.

“We’re going to regroup,” she said. “This isn’t over by any means.”

She said her group might pursue legal challenges or petition for another referendum.

Opponents argued that fluoride is a toxic chemical that poses many health threats, from cancer to brittle bones and discolored teeth.

The referendum capped a three-month campaign to lift Cumberland’s fluoride ban, led by local dentists, doctors and business groups. The Allegany/Garrett Dental Society got the issue on the ballot by gathering more than 3,000 signatures by early March.

Cumberland first voted to ban fluoride from its water in 1962. The mayor and City Council lifted that ban in 1988 after a hotly disputed referendum. After a lengthy court battle, the city’s water was treated for two months until voters reinstated the ban and ousted a pro-fluoride mayor.

The latest fluoride debate occurs a few months after tiny Mountain Lake Park in Garrett County decided to begin treating its water. Frostburg’s City Council narrowly rejected a request by the Allegany dental group to lift that city’s fluoride ban, but the ban has become a central issue in a municipal election to be held June 6.

In Cumberland, dentists, doctors and health care workers went door to door during the weekend, handing out fliers noting that Allegany children have the most cavities in the state, 50 percent more than youngsters living in communities that drink fluoridated water.

Fluoride advocates also filled local radio air waves with commercials featuring doctors and dentists urging a yes vote. Proponents contended that Cumberland’s resistance to the widely accepted public health measure was retarding the community’s progress.