- A lot of people think I'm Bill Cosby, but I'm really Tooth Decay. I'm Tooth Decay, but, uh, I'm actually on vacation. Especially with the teeth I've been working with here. (hand smacks) Mainly because some wise guy has been brushing after every meal and I think the thing that hurts me the most is the fact that he's using Crest. Yeah. See, Crest has fluoride. You see, it makes teeth hard. The enamel, you can't get anything. You hit, you hit, you hit, and only thing left for me to do is just wait for a mistake and when I get that mistake I'm gonna tear it to... Here it comes again, right after the meal. Gonna get another little bath. Fighting cavities is the whole idea behind Crest.