A prominent dentist and Department of Health staff said Thursday adding fluoride to drinking water will help reduce cavities among Dutchess County’s poor children, but the Dutchess County Board of Health balked at promoting the fluoridation of public water supplies.

Federal health agencies call fluoridation one of the most important public health achievements of the century. But it has been controversial as fluoride has become more widely available in other forms and as some studies have raised concerns that overexposure can harm health.

Poughkeepsie, the county’s largest water system, is the only one to add fluoride. Fluoridation is suspended there until September, as the plant installs a separate facility for handling fluoride, which can be hazardous to workers in its raw form.

Health Department staff said Beacon and Poughkeepsie have the most to gain by fluoridation because both have public water supplies and significant populations of low-income children who may not receive regular dental treatment.

Fluoride in water strengthens teeth only during childhood tooth formation. Most consider it unnecessary for any child receiving regular pediatric and dental treatment.

“People who see the dentist regularly probably have no real need for fluoridation,” said William Kirtland, a Hyde Park dentist with 33 years of experience, who has served in leadership roles for local and state American Dental Association chapters. “My main concern is the poor.”

Some board members questioned whether fluoridation would be more effective than subsidizing other treatments, such as fluoride vitamins, since many poor county residents live in rural areas served by well water. Some questioned the cost of installing fluoride injection systems at smaller water plants. Others questioned the safety of fluoride, given studies such as a March National Academy of Sciences analysis which said over- exposure to fluoride may lead to tooth disease and bone fractures.

The discussion ended with no vote. Board Chairman Harry Lynch said the department should move on without the board’s input.

“If he (Caldwell) and the department thinks it’s a good idea for the City of Poughkeepsie and the City of Beacon, that’s his call. That’s their call,” said Lynch, a Beacon resident.

Reached after the meeting, Beacon Water Superintendent Jamie McCollum said he opposes fluoridating Beacon’s water.

“I just think as water purveyors, we’re here to provide safe, potable water,” he said. “I don’t think we should play surgeon general and tell people what they should be drinking.”