Lost half a tooth need to take pictures to check the tooth defects, if the root does not appear longitudinal crack defects, you can consider root canal treatment after the pile core crown repair, the situation is serious need to extract the tooth.
Lost half a tooth may be traumatized or biting and eating too hard food caused by dental defects, general defects are large, the pulp chamber will be exposed, film examination if the root of the tooth is not defective longitudinal fracture, the tooth pulp chamber bottom is intact, you can consider root canal treatment after the crown restoration.
If the tooth is missing, the pulp chamber is incomplete or the root is damaged, the tooth can not be retained, the tooth needs to be extracted as soon as possible for prosthetic restoration. It is recommended to go to the hospital as soon as possible to avoid pain.