It's the 21st century, do we actually need teeth?

Shit. This has never happened to me before. I just broke a tooth. On a popcorn seed. It is one of my back molars, and it already had a filling. I am worried that if the filling falls out in my sleep I will be in horrible pain. I'm going to call the dentist first thing in the morning, but I don't know what to do for the time being. All I know is, if this, in anyway interferes with the Weezer/Tenacious D show I will NOT be a happy man.