I've had that dream a ton. I think people dream it, because it's something you think about. I actually fear it, but I don't know if that's your case or not. But it has no meaning. Dreams are just that, dreams.
I am in no position to judge, but anything you can remember from that dream will help you find out. I am guessing that your subconscious is telling you brush your teeth more? I don't know. Only you can figure it out.