After a traumatic tooth loss, if the tooth is not severely broken, it should be reimplanted as soon as possible. Therefore, patients should bring their lost teeth to the hospital as soon as possible for reimplantation. In the process of coming to the hospital, the lost tooth should be properly preserved, and can be cleaned and placed in the mouth or in liquid such as milk or tap water. Dental traumatology is a disease in which the hard tissues of the teeth, pulp or periodontal tissues are acutely damaged by a sudden mechanical force. Dental trauma can destroy one tissue alone or involve multiple tissues at the same time. A variety of factors can lead to dental trauma including collision with hard objects during a sudden fall, violent collisions in sports, traffic accidents and violence. Children are also prone to dental trauma when they collide or fall during learning to walk, play sports or games. The clinical characteristics of dental trauma are characterized by different degrees of damage to the hard tissues of the teeth, pulp or periodontal tissues. In trauma, the hard tissues of the tooth may be fractured, root fractured, or partially crowned, with or without pulp exposure. Pulp tissue may be filled with blood, ischemia, and fractured in trauma, and the exposed pulp may be infected by bacteria, eventually leading to pulp necrosis. Periodontal tissues may be filled with blood, bleeding or rupture of periodontal ligaments, bleeding or tearing of gums, fracture of alveolar process and alveolar fossa of different degrees, etc. in trauma. Therefore, dental trauma in emergency treatment should include multidisciplinary treatment concepts and means such as dental preservation and restoration, pulpal injury treatment, acute periodontal injury treatment, oral surgery, pediatric dentistry, and aesthetic dentistry, so the scope of clinical diagnosis and treatment and research involved in dental trauma is closely related to multiple disciplines.