Regenerative Endodontics Maintained Arrest of External Inflammatory Root Resorption After Secondary Concussion Injury: A Case Report.

This report highlights the unique occurrence of secondary trauma to a tooth previously treated with regenerative endodontic therapy (RET) and the successful outcome following this secondary injury. A 10-year-old girl sustained initial trauma to her maxillary central incisors. Tooth 11 sustained a complicated crown fracture and was treated with pulpotomy, which promoted complete root closure. Tooth 21 initially presented with an uncomplicated crown fracture; however, subsequent radiographic examinations revealed external inflammatory root resorption (EIRR) and periapical periodontitis. RET was performed to halt EIRR, and follow-up radiographs confirmed complete healing, indicated by a well-defined border around the resorption surface and the absence of apical radiolucency. Seven months after the initial trauma, the patient experienced a second injury, resulting in the concussion of both Teeth 11 and 21. No intervention was needed, but the teeth were closely monitored clinically. At the 26-month follow-up, both teeth remained asymptomatic with no pathological findings. This case demonstrates that RET effectively arrests EIRR in a short timeframe and maintains tooth stability even after subsequent mild trauma.