Regenerative endodontic treatment for premolars with apical root segment separation and extensive periapical lesions secondary to severe inflammatory root resorption: A report of two cases.

Inflammatory root resorption (IRR) frequently causes hard-tissue defects within the root canal system. The present report describes two cases in which regenerative endodontic treatment (RET) was used to manage premolars complicated by severe IRR, apical root segment separation and extensive periapical lesions. The first case involved an 11-year-old male patient with a fractured premolar (tooth 20) that exhibited IRR-induced apical segment separation. Case 2 involved a 15-year-old male patient presenting with severe IRR in tooth 20, characterized by an open, anomalous apical foramen and a large periapical lesion. Both teeth were managed by RET. In case 1, a regenerative scaffold was created by inducing periapical bleeding. In case 2, due to inadequate periapical bleeding, an alveolar-derived autologous blood clot obtained via aspiration from the maxillary terminal alveolar bone was utilized as the scaffold. Clinical and radiographic outcomes were documented over 2- and 3-year follow-up periods, respectively. At the 2-year follow-up in case 1, the tooth exhibited complete resolution of clinical symptoms, healing of the periapical lesion and arrest of IRR. Radiographic assessment revealed re-approximation of the apical root segment separated from the main root canal. However, the newly mineralized tissue deposition was insufficient to fully restore root continuity. At the 3-year follow-up in case 2, the patient remained asymptomatic, with complete healing of the periapical lesion and arrested IRR. These two cases suggest that RET may be beneficial for severe IRR complicated by apical root segment separation and large periapical lesions; however, further clinical studies are warranted to confirm these findings.