The standard amount of fluoride in U.S. tap water is 0.7 milligrams per liter. That’s it. It’s like finding exactly seven grains of salt in a giant pool of water.
This tiny number is the Goldilocks zone for your teeth. Too little, and cavities throw a party. Too much, and you get weird white spots (more on that later).
The U.S. Public Health Service picked this number in 2015. It’s the sweet spot for fighting cavities without turning your smile into a chalky mess.
