When Tristen Boyer recently had a couple of cavities filled, her dentist suggested she get fluoride treatment afterward. She has Crohn’s disease, which puts her at increased risk for tooth decay.

Kennedy Jr. Medical consensus says fluoride is harmless at levels found in drinking water and helps prevent tooth decay. Opposition to fluoride hinges on claims of toxicity, or that adding it to ...

Fluoride didn’t make much of a splash in the public eye when fluoridation trials began in 1945. The first run only reached about 232,000 Americans at the time. Nearly a decade later, the number ...