Iranian Dental Association Journal of Iranian Dental Association 3060-8201 37 3-4 2025 10 01 Management of Severe External Inflammatory Root Resorption in Replanted Maxillary Incisors Following Delayed Endodontic Intervention: A Case Report 70 76 10.34172/jida.2290 EN Mohammad Ali Ketabi https://orcid.org/0000-0002-9800-0038 Shahriar Yadolahi Farsani https://orcid.org/0009-0002-9803-9618 Journal Article 10.34172/jida.2290 2025 10 09 2025 10 24 Abstract Background and Aim: Avulsion with replantation of permanent teeth carries a high risk of external inflammatory root resorption (EIRR). This case report outlines the management of severe EIRR in replanted maxillary incisors after delayed endodontic care and an extended period of splinting. Case Presentation: A 16-year-old male presented with a 3-month history of anterior maxillary pain and swelling. Six months earlier, teeth 21 and 22 (FDI) had been avulsed in a road traffic accident, replanted after more than one hour, and stabilized with a flexible splint for six months. Radiographic examination revealed severe EIRR in both teeth and an acute apical abscess at tooth 22. Endodontic treatment was completed over three visits via an intracanal calcium hydroxide (CH) dressing, followed by obturation with a calcium–silicate–based bioceramic (Cold-Ceramic). At the 14-month follow-up, radiographs demonstrated complete periapical healing with replacement resorption. The teeth remained functional and asymptomatic. Conclusion: When endodontic treatment is initiated late, the staged use of CH may aid in the resolution of apical pathology and help maintain function in replanted teeth with EIRR. Extended splinting may be related to replacement resorption; therefore, stabilization should be flexible and time-limited.