This case report aims to present the early clinical and radiographic outcomes of nonsurgical endodontic retreatment performed using a bioceramic root canal sealer in a previously treated mandibular first molar (#46) exhibiting persistent symptoms. A 23-year-old systemically healthy female patient presented with a several-day history of spontaneous pain in the mandibular right first molar, which intensified at night. Clinical examination revealed tenderness to percussion. Periapical radiographic evaluation demonstrated inadequate and non-homogeneous root canal obturation associated with a periapical radiolucent lesion.Nonsurgical retreatment was performed in two visits. Following removal of the previous root canal filling material and chemomechanical preparation, calcium hydroxide was placed as an intracanal medicament. At the second appointment, the root canals were obturated using a bioceramic sealer in combination with gutta-percha.At the three-month follow-up, the patient was asymptomatic, and radiographic examination revealed a significant reduction in the size of the periapical radiolucency, indicating favorable early periapical healing.