Fluoridation is still a hard sell in Mass.

Voters in Springfield, Worcester, and elsewhere have repeatedly, and sometimes resoundingly, thwarted bids to put fluoride in their water, rejecting the entreaties of dentists and health directors that the chemical prevents rotten teeth.

Deborah Burns, as gregarious as she is passionate, remembers the pair of pumps she ruined one Election Day nearly three decades ago as she trod a sidewalk at a polling station here, evangelizing on behalf of fluoride in the water.

“Some people listened,’’ she recalled, “but a lot of people were saying we were trying to poison them, poison their children, poison the water.’’ Her side lost.

Burns was training to be a dental hygienist back then. Now, she runs the No Tooth Left Behind clinic, where students arrive with mouths cratered by three, four, even five cavities. It is, she said, the legacy of poverty and a lack of fluoridated water.

In the past, fluoridation has been used by critics to evoke the specter of sinister forces and communism and Dr. Stangelove. Today, the debate — especially in New England, with its don’t-tread-on-me ethos — is just as likely to pivot on perceptions of individual choice versus collective good, which fueled earlier debates over seat belt laws.

The battle has percolated for so long that the two sides are like a bickering couple whose positions have hardened beyond compromise.

From Dr. Stephen Dean, a Springfield chiropractor who has fought fluoridation since the 1960s: “I don’t base my resistance to fluoride on science. I base it on common sense. Even if it has no ill effects — which it does — I would not force anybody to take a chemical through the water supply for the rest of their life.’’

From Helen Caulton-Harris, top health official in Springfield for 14 years: “I see the faces and hear the voices of the most vulnerable people in the Commonwealth. To not be able to put in place good prevention strategies that the science tells us will have a major impact on residents’ quality of life is really heart-wrenching.’’

An arc of cities and towns extending south of Boston and onto Cape Cod don’t fluoridate their water, nor do most in Western Massachusetts, some because they don’t have public water supplies.

The absence of fluoridated water in so much of Massachusetts dismays health officials, who at the same time feel constrained by the tradition of local rule.

Specialists cite years of research they say attests to the health and economic benefits of fluoride, which acts like a magnet for other minerals that protect teeth from deterioration.

Studies, including one published last year by European scientists, have found that communities with fluoridation have a 20 to 40 percent lower incidence of dental decay. The recent report suggested fluoridation may also reduce the higher burden of cavities and gum disease among the poor, who have limited access to dental care.

In big communities, it costs about 50 cents a person annually to fluoridate water. But a 2001 study by the US Centers for Disease Control and Prevention concluded that communities with fluoridation saved as much as $18.62 per resident in yearly dental expenses.

Proponents maintain their case has been strengthened by evidence showing the mouth is a window into the rest of the body. Expectant mothers with gum disease are more likely to deliver too early. And poor oral health has been shown to put patients at risk for cardiovascular ailments.

When fluoride was first introduced to Massachusetts in 1951 and for a couple of decades hence, the health arguments held great sway. “Now, it’s much slower and harder to change people’s minds,’’ said Dr. Rob Compton, a vice president at the insurer Delta Dental of Massachusetts.

Fluoridation foes base their opposition on both health concerns and issues of personal liberty. There is, they argue, fluoride in toothpaste, fluoride in mouthwash, fluoride treatments that dentists can order.

“We support the voluntary use of fluoride — we’re not sitting around saying we don’t want people to have good oral health,’’ said Linda McLaren, president of Massachusetts Communities for Pure Water, which leads the charge against fluoridation. “That’s really where our heart is: the right of citizens of this state and everywhere to choose what they want to put into their own body.’’

But their arguments frequently go beyond that. They point to a controversial Harvard University study from five years ago that found a potential association between fluoride exposure and an extremely rare bone cancer in boys, although not in girls. And they also note that federal disease trackers have discovered an increase in fluorosis, a childhood condition that results from too much fluoride and that can cause tooth discoloration.

Dr. William Bailey, the CDC’s dental officer, said most cases of fluorosis are mild but acknowledged authorities would like to reduce its incidence.

“As always with fluoridation from the beginning years, you have to weigh the chances of fluorosis and any adverse effect like that, and the benefits,’’ Bailey said.

The last time Springfield went to the polls to decide fluoride’s fate was in 1983, when it was trounced. In 2000, the city’s Public Health Council declared an oral health crisis and spent the better part of five years trying to nurture public support for the cause. The council voted in 2005 to add fluoride, but the measure never went further, largely because other cities that share Springfield’s water supply failed to support it.

Instead, the health department in 2006 opened the No Tooth Left Behind clinic in a nook of the Germán Gerena Community School, situated in a neighborhood that was the state’s poorest in the 2000 Census.

Each year, 500 to 600 children are treated. There are cleanings and fillings, extractions and root canals of young mouths described as “bombed out’’ from cavities. Chester Thrower’s son, Kenyatta, 11, and daughter, Chestina, 10, have had cavities filled and teeth sealed.

“Just a little bit of fluoridated water would go a long way to eliminating the cavities that lead to other ailments and discomfort,’’ the father said. “We need the fluoridation, and I don’t know why we don’t have it.’’(9.29.2010) Stephen Smith can be reached at stsmith@globe.com