After over three hours of debate, the Board of Health voted Monday night to lower the amount of fluoride in the town’s water supply.

By a 3-1 vote, with Chairman Thomas Klem opposed and board member Elisabeth Brewer having left the meeting early, the board agreed to reduce the target concentration of fluoride in the town water supply to 0.7 parts per million, subject to staff review.

The vote followed a lengthy discussion with Myron Allukian, the director of oral health with the Boston Public Health Commission and an assistant clinical professor at the Goldman School of Dental Medicine at Boston University.

Allukian shared the many positives of community water fluoridation, as board member Michael Bean continued to grill him on some of the side effects of excess fluoridation.

Foremost among those side effects is fluorosis, a disturbance of dental enamel caused by excessive exposure to high concentrations of fluoride during tooth development. Mild forms of fluorosis show up as tiny white streaks in tooth enamel. More severe forms of fluorosis are discoloration or brown markings on teeth.

“Is it possible to give informed consent?” Bean asked. “How do we tell people in Wayland that if you drink water, there’s a chance you could develop moderate fluorosis?”

While residents packed the Board of Selectmen meeting next door in the Town Building to discuss the firing of Town Administrator Fred Turkington, many of the dozen people in attendance at the Board of Health were community dentists opposed to any change in the amount of fluoride in the town’s water supply.

However, resident Mike Lowery shared his support for lowering the amount of fluoride in the public comment session of the Board of Health meeting.

“I view this as a problem of medical ethics,” Lowery said. “I believe I am being asked to take medication I didn’t request. Because I don’t care to have fluoride in my water, I purchased a water filter and the filters that remove the fluoride cost my family $50 a year. Not everyone can afford $50 a year to remove the fluoride, so I’m sure there are some people who don’t have this option.”

Allukian was direct in his support of fluoridation.

“We still have a disease that affects a lot of people,” he said. “Most people get new disease every year unless they are scrupulous about oral hygiene, scrupulous about using fluoride, and scrupulous about seeing the dentist every year. The average American consumes 140 to 150 pounds of sugar every year. Many kids get it through sugary beverages.”

He added, “The best preventive measure we have is community water fluoridation.”

Four communities in Massachusetts (Duxbury, Lincoln, Templeton and Scituate) all considered ending the use of fluoride in community water supplies, but all agreed to continue using it.

“I strongly urge you to talk to those communities where it was challenged,” Allukian said.