Injuries to the mouth can cause teeth to be pushed back into their sockets. Vahid A. Atabakhsh, DDS or your general dentist may reposition and stabilize your tooth. Root canal treatment is usually started within a few weeks of the injury and a medication, such as calcium hydroxide, will be placed inside the tooth. Eventually, a permanent root canal filling will be implanted.
Sometimes a tooth may be pushed partially out of the socket. Again, your endodontist or general dentist may reposition and stabilize your tooth. If the pulp remains healthy, then no other treatment is necessary. Yet, if the pulp becomes damaged or infected, root canal treatment will be required.
If an injury causes a tooth to be completely knocked out of your mouth, it is important that you are treated immediately! If this happens to you, keep the tooth moist. If possible, put it back into the socket. A tooth can be saved if it remains moist. You can even put the tooth in milk or a glass of water (add a pinch of salt.) Your Endodontist may start root canal treatment based upon the stage of root development. The length of time the tooth was out of your mouth and the way the tooth was stored, may influence the type of treatment you receive.
Injuries in children
An injured immature tooth may need one of the following procedures to improve the chances of saving the tooth:
This procedure encourages the root to continue development as the pulp is healed. Soft tissue is covered with medication to encourage growth. The tip of the root (apex) will continue to close as the child gets older. In turn, the walls of the root canal will thicken. If the pulp heals, no additional treatment will be necessary. The more mature the root becomes, the better the chance to save the tooth.
In this case, the unhealthy pulp is removed. The doctors place medication into the root to help a hard tissue form near the root tip. This hardened tissue provides a barrier for the root canal filling. At this point, the root canal walls will not continue to develop, making the tooth susceptible to fractures so it is important to have the tooth properly restored by your dentist.
Vital pulp Regeneration (regenerative Endodontic procedure)
This is a biologically based procedure designed to replace damaged structures, including dentin and root structures, as well as the nerve cells. In the immature teeth with pulpal necrosis, this optimally translates to complete restoration of pulpal function and subsequent completion of root development. Case studies have shown that healing of apical periodontitis, continued development of the root apex and increased thickness of the root canal wall of immature teeth with pulpal necrosis can occur after regenerative endodontic procedures.
This procedure is further explained on the AAE website link below;