Influence of the Cause of File Fracture on the Successful Removal of Fragments from Root Canals: An In Vivo Study

The purpose of this investigation was to establish a clinical diagnosis of the cause of instrument fracture and to evaluate its impact on fragment removal success. One hundred cases of fractured endodontic instruments were analyzed to determine the relationship between fracture cause (flexion, torsion, or combined) and removal outcomes. A diagnostic protocol was developed to classify the fracture mechanism based on radiographic findings, clinical observations, and instrument-related parameters. Fragment length, intracanal location, and removal time were recorded. Torsion was the most frequent cause (54%), followed by combined fracture (33%) and flexion (13%). Flexion-related fragments were significantly longer, located in more accessible areas, and exhibited lower mechanical retention, resulting in shorter removal times (mean: 19.62 min). In contrast, torsion-related fragments were shorter, showed greater retention, and required longer removal times (mean: 32.98 min). Statistical analysis demonstrated a significant association between fracture cause, fragment location, and removal time. The fracture mechanism may serve as a predictive clinical factor for fragment removal difficulty. Early identification of this parameter can improve treatment planning and optimize clinical resource management.