ASHLAND – Would adding fluoride to the town’s drinking water make residents smile or gnash their teeth?

Town health officials intend to find out as they weigh whether Ashland should join the majority of towns in MetroWest with fluoridated water.

Ashland last considered fluoridation about a decade ago, when a dentist sat on the Board of Health, said board member Reginald Mimms. But amid health concerns about the practice, the proposal went nowhere, he said.

“Over the course of years, fluoridation has become much more mainstream,” Mimms said yesterday. “In that regard, Ashland seemed to be left behind.”

The board began looking into fluoride last spring, when Health Agent Mark Oram said he received information on the chemical at a conference held by Community Health Coalition of MetroWest.

Oram said he later attended a Massachusetts Dental Association conference to learn more on the subject.

“You could spend hours on this, on the pros and cons,” Oram said. “I think it’s up to the board to take everything into consideration and determine if it’s something we should be doing.”

The Board of Health is still in the early stages of researching fluoridation, but will eventually hold a public hearing to find out what residents think, Oram and Mimms said.

Framingham, Natick, Marlborough, Hudson, Holliston, Wayland, Sudbury, Wellesley, Newton, Dedham and Waltham have fluoridated water.

Several of those communities are served by the Massachusetts Water Resources Authority. The MWRA adds one part fluoride per million parts water to its supply, according to the agency’s Web site.

Fluoride is added to water in 137 of the state’s 351 cities and towns, Oram said.

Fluoridation has proved controversial in other communities, including Natick in the late 1990s, and New Bedford, which began adding fluoride to its water earlier this year after nearly 20 years of debate.

Proponents argue fluoride is a relatively cheap, effective and harmless way to prevent dental decay. That is supported by the Centers for Disease Control, state Department of Public Health, American Dental Association and other experts.

Critics say fluoridation carries health risks ranging from cancer to damage to the enamel of developing teeth; is a form of mass medication; and has questionable benefits.

Fluoridation advocates say many supposed health risks are based on myths or flawed research, including a study by Harvard University researchers last year linking fluoridated water to a rare form of bone cancer in young boys.

A proposal to mandate fluoridation in most water supplies statewide died on Beacon Hill last year.

Mimms said that to him fluoridation makes sense and is a way to help prevent decay among “different economic levels” in Ashland.

“People should have the right to voice their opinion, and then we’ll make the best informed decision we can,” he said.