There's fluoride in your toothpaste and even in your water. But how does it work to keep teeth healthy? Let's find out.

Fluoride is a natural element found in the earth's crust as well as in water and air. Decades ago, scientists discovered that kids who naturally had more fluoride in their drinking water had fewer cavities. In the mid-1940s, communities started to put more fluoride in their water supplies to protect people against tooth decay.

Fluoride helps because, when teeth are growing, it mixes with tooth enamel — that hard coating on your teeth. That prevents tooth decay, or cavities. But fluoride can help even after your teeth are formed. It works with saliva to protect tooth enamel from plaque and sugars. By using fluoride toothpaste, for instance, everyone can enjoy some cavity protection. Fewer cavities means healthier teeth when you're an adult — and less chance of having to wear false teeth (dentures) when you're old!

So how do you get your fluoride? Ask your dentist the next time you have an appointment. In addition to fluoride toothpaste, he or she might recommend a mouthwash that has fluoride in it. And if your drinking water doesn't have fluoride in it, your dentist might suggest supplements — which are like vitamins containing fluoride.

Just how effective is fluoridated water? Thanks to it, dentists say half of kids between 5 and 17 have never had a cavity in their permanent teeth. We hope you're one of them!

Reviewed by: Steven Dowshen, MD
Date reviewed: October 2012