We’ve heard about cavities since we were kids. Yet our understanding of what they are, how we get them, and what we can do about them is often somewhere back in the third grade.

Myth: No Pain, No Problem If my teeth don’t hurt, they’re fine, right? Not always. “By the time something hurts, it’s gone way too far," says Matt Messina, DDS, a dentist in Fairview Park, OH. “By the time it hurts, then the nerve of the tooth is becoming annoyed and involved, so we’ve taken a simple filling and maybe taken it closer to a root canal or something like that.” That’s why regular checkups are so important. “I think we have pretty much discredited the notion that, ‘Wait till it hurts,’” says Andy Marashi, DDS, a Seattle dentist. “Decay does not necessarily hurt.” You know what really hurts? “The longer it goes,” Marashi says, “the more expensive it is.”