The town that is home to the largest number of nonprofit institutions may also have the fewest cavities.

Oak Bluffs is the only town on the Island that fluoridates its public water supply. The Wampanoag Tribe of Gay Head (Aquinnah) also adds flouride to the well water that serves the tribal housing project in Aquinnah.

Tisbury and Edgartown opt to not fluoridate their public water supplies. And West Tisbury, Chilmark and Aquinnah have no public water supplies (outside of the tribe’s housing project).

Parents in those towns who have children aged six months up to 16 years old must find alternate ways of ensuring that their children’s tooth enamel grows in strong and acid-resistant to prevent tooth decay.

And as a result, Island pediatricians and dentists write hundreds of prescriptions for fluoride drops, chewable fluoride pills and multivitamins with fluoride.

“The decay rate goes way down among people who have fluoridated water,” Edgartown dentist Garrett Orazem said. “In towns where you don’t have a public water supply, if you want your kids to have the right amount of fluoride, you’ve got to add it to your kids’ diet,” he added.

“It takes more work,” said Dr. Orazem, who raised two children in Edgartown. “Getting fluoride to a kid every day is difficult.”

The fluoride controversy has been relatively quiet on the Island since the 1960s, when fluoride’s safety and effectiveness at preventing tooth decay was proved beyond doubt and the government was pushing hard for fluoridation in every town in the country. The U.S. Supreme Court upheld the constitutionality of what critics called mass medicating and the Gazette was inundated with letters containing viewpoints ranging from adamant support of water fluoridation to vehement opposition of what was termed a Soviet scheme to debilitate American youth.

Today there is less fear of communist conspiracies and fewer people try to blame fluoride for AIDS, cancer or mental retardation.

But many Islanders are still skeptical and some question the necessity of mass water fluoridation when other methods of obtaining fluoride are available.

“From a water professional point of view, I just don’t believe in putting anything in the water that’s not necessary for water quality. Naturally, if we found the cure for cancer and we could put it in the water, I’d be all for it,” Edgartown water superintendent Fred R. Domont said this week.

“There are so many alternatives nowadays that when I was a child didn’t exist – fluoride toothpaste, fluoride treatments,” Mr. Domont continued. “And I know sometimes children get neglected, and those are the children that benefit from fluoride in the water,” he added.

But Mr. Domont said fluoridating the water is still not worth it, even if a population of children would be helped by it.

“I would do my darndest to make sure people didn’t vote for fluoridation in Edgartown,” he said.

Most health care professionals take an opposite view.

Dr. Orazem points out that fluoridation of drinking water was listed as one of the ten great public health achievements of the 20th century by the weekly publication of the Centers for Disease Control.

“Fluoride is by far the most heavily researched public health issue in America, so I’m very comfortable in recommending it as a safe thing,” said Dr. Orazem, who has practiced on the Island for 26 years. “I support water fluoridation and the reason I do is that I consider it a natural way of having people have optimal teeth that are easy to take care of.

“It’s ironic that dentists in the United States have worked so hard to support something that has given us less work to do,” he continued. “Its effects are dramatic. The reduction in tooth decay between communities that were fluoridating and communities that were not were on the order of a 50 per cent reduction in tooth decay – and maybe as much as 60 per cent. That’s nothing to mess around with.”

He gave a detailed explanation of how flouride is metablolized in a way that allows the human body to build strong tooth enamel.

When weighing the merits of water fluoridation, consider bluefish, he said.

“They have famously strong teeth and they live in an environment that has fluoride in it,” Dr. Orazem said. “And the fact that there is fluoride present in ocean water makes me think that fluoride is a particularly natural way of protecting our teeth.”

Some home water filters may negate the benefits of flouride; the same is true for people who rely heavily on bottled water at home. Some bottled water companies like Poland Spring have responded by manufacturing fluoridated water – but pharmacists and physicians caution those already taking fluoride supplements to avoid it. Too much fluoride can cause permanent tooth discoloration.

“I’ve bought it by mistake, so you have to read the label carefully,” Conroy Apothecary pharmacist and co-owner Tamara Hersh said of fluoridated bottled water. “Most children [up-Island] do have fluoride supplements prescribed by either their pediatrician or their dentist,” she added.

A 2005 study by Island Health Inc. showed that the general dental health among Island children is below the state average. The study led Island Health to obtain a grant for an in-school dental program called Vineyard Smiles.

Since starting up last fall, the program has served about 240 Island children with exams, cleanings, fluoride treatments, sealants and fillings.

Vineyard Smiles director Sarah Kuh – who is also director of the county Health Care Access Program – said poor dental health on the Island stems in part from a shortage of dentists and dental specialists on the Island and the absence of dentists who accept Mass Health, insurance for people with low incomes. A dental center at the Martha’s Vineyard Hospital closed in June 2004 with a waiting list of 1,000 low-income people, she said.

“Fluoride is one of the shining classic examples of health care successes,” Ms. Kuh said. “It’s hard to argue with the usefulness from a public health standpoint of having fluoride in public drinking water when you consider dental disease is the number one childhood disease.”