What should I do if I knock out a tooth?
You have a better than 80 percent chance of saving your tooth if you can get to your dentist with the tooth within a half hour. Here are some things to remember: Rinse the tooth off with warm water. But don't scrub the tooth. You might scrub off fibers on the root that are important to re-planting the tooth in its socket. Keep the tooth moist by wrapping it in either gauze (one reason why it's good to have gauze in the house) or tissue dampened in warm water. If you can easily replace the tooth into the socket, do that.
Some experts recommend just putting the tooth back in your mouth under your tongue during the ride to the dentist. That's fine, too. Just don't swallow the tooth. Your pharmacy may also carry one of the liquid media that are available for just such an emergency. You won't have time for a trip to the pharmacy, however, so you might consider keeping one of these liquid media on hand.
It's likely that you got a laceration with this injury. Press a cold damp cloth with moderate pressure over a cut lip.