Dental avulsion is the complete displacement of a tooth from its socket in alveolar bone owing to trauma. The treatment for permanent teeth consists of replantation, immediately if possible. Deciduous teeth should not be replanted due to the risk of damaging the permanent tooth germ. Immediate replantation ensures the best possible prognosis but is not always possible since more serious injuries may be present. Studies have shown that teeth that are protected in a physiologically ideal media can be replanted within 15 minutes to one hour after the accident with good prognosis. The success of delayed replantation depends on the vitality of the cells remaining on the root surface. In normal conditions, a tooth is connected to the socket by means of the periodontal ligament. When a tooth is knocked out, that ligament stretches and splits in half. Maintaining the vitality of the cells that remain attached to the root surface is the key to success following replantation. Years ago, it was thought that the key to maintaining root cell vitality was keeping the knocked-out tooth wet, thus giving rise to storage media recommendations such as water, the mouth and milk. Recent research has shown that one of the key elements for maintaining vitality is storing the tooth in an environment that closely resembles the original socket environment. This environment is one that has the proper osmolality (cell pressure), pH, nutritional metabolites and glucose. There are scientifically designed storage media that provide this environment. These storage media are now available in retail products. Use of devices that incorporate the ideal storage media and protective apparatuses have increased the success rate of replanted knocked-out teeth to over 90% when used within sixty minutes of the accident.
The best method for the prevention of knocked-out teeth is the use of helmets and mouth protectors. Mouth protectors can be very inexpensive, however, the compliance rate for their use is poor. Studies have shown that, even when mandated, athletes and other high risk individuals often will not use them. Also, even with their use, mouth guards can be knocked-out, leaving the user unprotected.
Dental avulsion is a real dental emergency in which prompt management (within 20–40 minutes of injury) affects the prognosis of the tooth. The avulsed permanent tooth should be gently but well rinsed with saline, with care taken not to damage the surface of the root which may have living periodontal fiber and cells. Once the tooth and mouth are clean an attempt can be made to re-plant in its original socket within the alveolar bone and later splinted by a dentist for several weeks. Failure to re-plant the avulsed tooth within the first 40 minutes after the injury may result in a less favorable prognosis for the tooth. If the tooth cannot be immediately replaced in its socket, follow the directions for Treatment of knocked-out (avulsed) teeth and cold milk or saliva and take it to an emergency room or a dentist. If the mouth is sore or injured, cleansing of the wound may be necessary, along with stitches, local anesthesia, and an update of tetanus immunization if the mouth was contaminated with soil. Management of injured primary teeth differs from management of permanent teeth; avulsed primary tooth should not be re-planted (to avoid damage to the permanent dental crypt).