Mel Rosenberg: What causes cavities?

When a team of archeologists recently came across some 15,000-year-old human remains, they made an interesting discovery: the teeth of those ancient humans were riddled with holes. So what causes cavities, and how can we avoid them? Mel Rosenberg takes us inside our teeth to find out. [Directed by Andrew Foerster, narrated by Addison Anderson, music by Devin Polaski].