CLEARWATER — One of the largest counties in Florida voted today to add fluoride back into the water supply, capping a lengthy debate over whether adding the chemical is beneficial for fighting tooth decay or toxic and an affront to personal liberty.

The Pinellas County Commission voted 6-1 to return fluoride to the water. It was removed in October, 2011.

“Shame, shame, shame,” one anti-fluoride resident yelled out after the vote.

The board reversed its decision because two new commissioners who ran on a pro-fluoride platform were elected in November.

The October 2011 move affected some 700,000 people and touched off a political controversy that pitted dentists and orthodontists against people who feel fluoride is harmful, even toxic, and that the county shouldn’t pay for residents’ personal health decisions.

Fluoride proponents say the chemical, which has been added to many U.S. water supplies for decades, prevents cavities and is safe. Opponents say it is toxic and that citizens should decide for themselves whether to use it for dental health.

Fluoride is a mineral that exists naturally in water and soil, and fluctuates depending on the day. Officials in Pinellas will add fluoride to bring the level up to the federal recommendations.

Norm Roche, the board’s lone dissenter, who had also voted against fluoride in the water in 2011, said he’s seen studies and science on both sides of the issue, and isn’t convinced that it’s safe.

“If there are questions, it should not go in our drinking water,” he said.

The fluoride will be added back into the water in March 2013. Officials said it will take that long to notify residents that the substance will be put back in the water supply.

About 100 people attended today’s meeting, some toting signs and oversized toothbrushes. Public comment on the issue lasted more than three hours.

Most of those in attendance were against putting fluoride in the water, claiming that it reduces IQ, exacerbates diabetes and causes people to be docile. Still others say elected officials shouldn’t make medical decisions for citizens.

“You seem to think you’re fit to make medical treatment decisions for me,” said Pamela Hummel of Clearwater. “That’s a matter for me and my doctor, me and my dentist, and you are intruding on that decision.”

Adrian Wyllie, chairman of the Libertarian Party of Florida, said he agrees that fluoride is good for teeth – but he doesn’t believe that the commission has the authority to add it to the water.

“You lack the authority to make medical decisions for the people of Pinellas County,” Wyllie said.

Many of the people who spoke in favor of the fluoride were dentists or dental professionals.

Karen Hodge, a dental hygienist, said that putting fluoride in the water is a good way to prevent cavities in people, especially children.

“When we’re talking about something that is so simple, safe, effective, cost-efficient, it’s a no-brainer,” she said.

Harvey Kerstein, a Clearwater dentist, said that he’s seen a huge difference in his patients who grew up with fluoridated water and those that haven’t.

“These patients who have not had fluoride have much higher decay rates,” he said. “Every person who has had teeth or expects to have teeth benefits from community water fluoridation.”

Added Johnny Johnson, a Palm Harbor dentist: “There’s no credible evidence that it’s unsafe.”

About 73 percent of the U.S. population drinks fluoridated water. In September, the city of Portland, Ore., voted to add fluoride to its water; it was the nation’s largest city without the substance.