Prognosis of replanted primary incisors after injuries

Between 1979 and 1997, 58 avulsed primary teeth were treated at the Pedodontic Clinic of Niigata University Dental Hospital. Among these, we replanted six avulsed incisors of four patients and treated two teeth of two patients replanted at other dental clinics. Referring to the clinical records, oral photographs and radiographs, we examined the injury age, cause of injury, condition of tooth storage, length of time until replantation, and also the prognosis after replantation. Three teeth of two cases remained until eruption of their permanent successors, and one tooth of one case remained under observation without extraction. Although the other four teeth of three cases resulted in extraction, no secondary infection was detected due to replantation. The following reasons were suspected for the poor prognosis of the four teeth. One avulsed tooth was not fixed immediately after replantation. One replanted tooth might not have been compatible with the alveolar socket. In the other two teeth, the periodontal vital tissues might have been removed before replantation. It is generally suggested that replantation of primary teeth is not a good option. However, from the present results, it was considered that replantation can be an effectual method when the condition of the avulsed primary tooth is suitable.