If you’ve been to a dentist or shopped for toothpaste, you’re familiar with fluoride. It’s one of those words like “anesthesia” that we don’t think about much, but we are sure a lot better off for having it around. The use of fluoride has resulted in a well-documented decline of cavities and tooth decay. But there are still folks who question its use. Here’s what we know about fluoride as a tool for dental health.