Management of a Separated Endodontic Instrument: A Case Report

AbstractInstrument separation during root canal treatment is a recognized procedural complication that can compromise effective canal disinfection and affect treatment prognosis. The increasing use of nickel-titanium (NiTi) rotary systems has heightened the incidence of instrument fracture due to cyclic fatigue and torsional stress. Management depends on fragment location, canal anatomy, degree of curvature, and the strategic importance of the tooth, with options includingretrieval, by passing, or intentional retention with periodic monitoring. This case report presents the successful management of a separated endodontic instrument in a 32-year-old male patient presenting with intermittent pain in the lower right posterior region following previously initiated root canal treatment of the mandibular first molar. Preoperative radiography revealed a metallic fragment lodged in the middle third of the buccal root canal, obstructing apical access. A diagnosis of symptomatic apical periodontitis was established. Treatment was performed under rubber dam isolation. Bypassing was accomplished using a size 10 K-file with copious sodium hypochlorite irrigation, followed by ultrasonic activation undernmagnification to loosen and retrieve the fragment. Cleaning and shaping were completed using rotary instrumentation, and obturation was performed with gutta-percha and resin-based sealer using the single cone technique. At follow-up, the patient was asymptomatic with satisfactory radiographic healing. This case demonstrates that a systematic, minimally invasive approach combining bypass and ultrasonicn retrieval can effectively resolve instrument separation with favorable outcomes.