It can happen in a contact sport, during labor intensive work or sometimes by just a freak accident when a tooth gets broken or knocked out. Seek emergency dental treatment immediately. For a broken tooth, rinse your mouth with warm water to clean the area. Use cold compresses on the area to keep any swelling down till you get to the dentist.
When a tooth gets knocked out completely, time is of the essence to get to the dentist. Be careful not to touch the root of the tooth to contaminate it. Hold the tooth by the crown. If the tooth is contaminated, rinse it gently with clean saline or water—don’t scrub it. Put the tooth in a container of milk and try to get to a dentist within 30 minutes. The dentist will want to properly implant the tooth right away. The longer the tooth is out of its socket the more likely your gum may regard it as a foreign object. If you can’t get to a dentist within that time, rinse off the tooth and gently place the tooth back into the socket. Avoid eating and get to the dentist as soon as possible.