Recently, I've seen a lot of traumatized teeth - chipped/cracked teeth or teeth that have been knocked out of place. The ADA (American Dental Association) commented on a recent CBS segment on The Doctors show where they discussed the "do's and don'ts" should a tooth become dislodged. Do not try to wash the tooth off with soap or soak it in any kind of peroxide. The tooth should be placed in a small container either containing saliva (yes, you read that right) or milk. Contact your dentist ASAP so that the tooth can potentially be re-implanted. If it has been under an hour since the accident, chances are good that the tooth can successfully be re-implanted and splinted back into place.
Always remember that during any sporting activity, it is always a good idea to wear a mouthguard (either an over-the-counter style or a custom fit one by your dentist) to prevent injury to your teeth.
-Eric Tyler, DDS