Regenerative Endodontics For Replanted Teeth With Root Resorption And Perforation

External root resorption (ERR) frequently complicates replantation of traumatized teeth. While calcium hydroxide remains the traditional treatment for external inflammatory root resorption, this case report presents the 6-year outcomes of regenerative endodontic procedures (REPs) in a trauma-replanted tooth (tooth #24) with severe ERR and root perforation. A 18-year-old male presented with persistent pain after replantation of an avulsed mature mandibular incisor. Referred for #24 management, clinical evaluation showed pulp necrosis and symptomatic apical periodontitis. Imaging revealed a single-rooted tooth with mid-root distal perforation (3.4×4mm) from severe external root resorption (ERR), accompanied by alveolar bone loss. Regenerative endodontic procedures (REPs) were performed, resolving clinical symptoms. Seven-year follow-up demonstrated root canal calcification/obliteration post-REPs, hard tissue deposition at the perforation site, and suspected replacement resorption. CBCT confirmed resolution of ERR-associated bone loss and reparative changes. Effective intracanal infection control is crucial. It is essential to remove invading granulation tissue, followed by calcium hydroxide medication to prevent reinfection, suppress tissue regrowth, and manage bleeding. The apical foramen should be enlarged to size 60, and when inducing apical bleeding, ensure that the blood clot remains stabilized above the perforation site. REPs may be used to manage trauma-replanted permanent teeth with a necrotic pulp associated with severe ERR and root perforation, offering a distinct approach compared to conventional methods.