Most of us know what's bad for our teeth. But some things you chew can make your mouth healthier.

12-year-old Ali Haymes has never had a cavity. Her mom Leslie says she takes after her father.

"My husband has great teeth, and she lucked out and got very healthy teeth," Leslie says.

But diet could be another reason for Ali's flawless smile.

"She doesn't like soda, and she doesn't like a lot of sweets," Leslie points out.

Ali adds, "I eat a lot of fruit and eat vegetables."

Crisp fruits and veggies act like nature's toothbrush, and manually clean the teeth.

What else should you be eating? Here's good news for the dairy state: Milk, yogurt and cheese! Dr. Mary Hayes with the American Dental Association says those foods act to neutralize cavity-causing acids in the mouth.

"Milk is basic, so if you have something acidic and you have some milk, you are going to bring yourself back to neutral more easily than if you just have an acidic diet all the time," Dr. Hayes explains.

Foods high in Vitamin C help prevent Gingivitis, the first stage of gum disease. Good sources include strawberries, kiwis, peppers, and of course, citrus fruits.

"In olden days if there was not enough Vitamin C they would get scurvy, and then they would have terrible mouth sores and lose their teeth," Dr. Hayes says.

Good news for folks with a sweet tooth: The oils in nuts and chocolate benefit your smile too.

Some dentists actually recommend you chew gum! Chewing sugarless gum for 20 minutes a day can actually help prevent tooth decay.