By David F. Murchison, DDS, MMS, Clinical Professor, Department of Biological Sciences;Clinical Professor, The University of Texas at Dallas;Texas A & M University Baylor College of Dentistry
(See also Introduction to Urgent Dental Problems.)
Teeth are commonly cracked (fractured), loosened, or knocked-out (avulsed) when people receive a strong blow to the mouth. Sometimes previously weakened teeth are fractured or loosened by chewing.
The upper front teeth are prone to injury and fracture. A person who has brief, sharp pain while chewing or while eating something cold may have an incomplete fracture of a tooth anywhere in the mouth. As long as the tooth is only cracked and a piece has not split off, the dentist can often correct the problem with a simple filling. More extensive fractures may require a crown, with or without root canal treatment.
If a tooth is not sensitive to cold air or water after an injury, most likely only the hard outer surface (enamel) has been damaged. Even if the enamel has been slightly chipped, immediate treatment is not required. Fractures of the intermediate layer of the tooth (dentin) are usually painful when exposed to air and food, so people with such fractures seek dental care quickly. If the fracture affects the innermost part of the tooth (pulp), a red spot and often some blood will appear in the fracture. Root canal treatment may be needed to remove the remaining injured pulp before it causes severe pain.
If an injury loosens a tooth in the socket or if the surrounding gum tissue bleeds a great deal, a person should see a dentist immediately, because the root or socket may be fractured. A loosened tooth that is repositioned and stabilized quickly usually stays in place permanently. Seriously loosened baby (deciduous) teeth in the front of the mouth are often removed to prevent harm to existing permanent teeth without losing space for the permanent teeth that are yet to erupt.
People who have knocked out baby or permanent teeth should be taken immediately to the nearest dentist. Knocked-out baby teeth should not be reimplanted because they may become infected and reimplanting these teeth may interfere with the eruption of the permanent tooth. However, a knocked-out permanent tooth requires immediate treatment.
The tooth should be gently rinsed under cold water for 10 seconds but should not be scrubbed, because scrubbing can remove the tissue on the root that is needed to help reattach the tooth. Then, the tooth should be placed back in its socket. If the person cannot replace the tooth in its socket, the tooth should be wrapped in a moistened paper towel or, better, placed in a glass of milk for transport to the dentist. (The milk provides a good environment to nourish the tooth.)
If the knocked-out tooth cannot be found, it may have been inhaled into the lungs (aspirated) or accidentally swallowed. A chest x-ray may be done to look for a tooth in the lungs, but a swallowed tooth is harmless, and x-rays are often not done to look for a tooth in the digestive tract. People with knocked-out teeth that are being reimplanted usually take an antibiotic for several days.
If a knocked-out permanent tooth is reimplanted within 30 minutes to 1 hour, the likelihood that it will stay healthy is good. After 30 minutes, the longer the tooth is out of the socket, the worse the chance for long-term success. The dentist usually splints the tooth to the surrounding teeth for 7 to 10 days. If the bone around the tooth also has been fractured, the tooth may have to be splinted for 6 to 10 weeks. Reimplanted teeth eventually need root canal treatment.