If a tooth is completely knocked out, time is of the essence. The tooth should be handled very gently, avoiding touching the root surface itself. If it is dirty, quickly and gently rinse it in water. Do not use soap, and never scrape or brush the tooth. If possible, the tooth should be placed back into the socket in the mouth as soon as possible. The less time the tooth is out of its socket, the better the chance for saving it. Call your endodontist for an appointment right away.