Lee County commissioners voted unanimously on Tuesday 4 to become the 40th Florida county to stop adding fluoride to drinking water. Spearheaded by Commissioner Cecil Pendergrass, the move flies against the advice of the American Dental Association and the American Medical Assocation.

Fluoride is a mineral long proven to strengthen teeth and prevent cavities when added to water in small amounts. Local utilities across the country have been putting fluoride in water since 1945 to help fight tooth decay. The CDC considers the practice one of the great public health achievements of the 20th century.

Hillsborough commissioners shot down a motion to remove fluoride from the county's drinking water. Why it matters: Conservatives have fashioned fluoride into an issue of medical freedom, leading communities across Florida and the nation to halt the practice of adding the mineral to drinking water.