So you've been told for years that eating lots of candy, junk food, and sugar will give you cavities in your teeth, but it's not actually the sugar itself that causes these holes in your teeth in the first place.
In fact, it actually has to do with tons of little microbes in your mouth that like to feast on the sugary yumminess of what you're eating. As a byproduct of the sugars they eat, they excrete acids, which are what cause the linings of your teeth to disintegrate and eat away.
By brushing your teeth and cleaning your mouth regularly, you not only kill off many of these microbes, but you wash away some of the acids that are harmful to your teeth over time.
So the next time you hear someone tell you that eating candy causes cavities, go ahead and let them know it's actually the little microscopic bacteria causing the cavities, and not so much the sugar you're eating. Although sugar may be a catalyst, those microbes are what are responsible for cavities.