Long-term retention of avulsed maxillary permanent incisors replanted after prolonged non-physiological storage.

Ankylosis and external replacement resorption (ERR) are two typical biological responses to delayed replantation of avulsed teeth in cases where adequate root canal treatment is performed. The patient's growth stage affects the progression of root resorption and the long-term outcome of the affected teeth. This case report describes the long-term outcome of an 18.5-year-old patient following an accident in which both of his maxillary central incisors were avulsed and replanted after four hours of non-physiological storage. ERR and ankylosis of teeth 11 and 21 were detected clinically and radiographically during the second year of follow-up. Sixteen years after replantation, replacement resorption was progressing very slowly, enabling functional tooth retention with favorable esthetics. Young adults, with delayed replantation of avulsed teeth, may benefit from tooth retention with slow ERR.