Comparative evaluation of success rate and operator variability in loop.based versus ultrasonic retrieval of fractured endodontic instruments: An ex vivo study

Introduction: Instrument separation remains one of the most challenging procedural complications in endodontics, potentially compromising disinfection and long-term treatment success. Conventional ultrasonic retrieval methods are technique sensitive and often dependent on operator experience. Recent advancements in loop-based techniques offer a potential alternative with greater control and reproducibility. This study aimed to compare the success rate and operator variability between loop-based retrieval versus ultrasonic-only method for removing fractured endodontic instruments under standardized ex vivo conditions. Materials and Methods: Forty extracted human mandibular molars were prepared with simulated mid-root fractures of ProTaper Gold F2 instruments. Samples were randomly divided into two groups (n-20 each): Group 1: ultrasonic-only retrieval and Group 2: ultrasonic troughing followed by loop-based retrieval. Two postgraduate operators with differing levels of retrieval experience performed the procedures. Success was defined as complete instrument removal within 60 min without procedural complications. Intergroup comparisons and interoperator variability were assessed using the Chi-square test. Results: Group 2 (loop-based retrieval) demonstrated a significantly higher success rate (95%) compared to Group 1 (70%) ( P = 0.037). Interoperator variability was notably lower in the loop group, with both experienced and novice operators achieving high success rates (100% and 90%, respectively), indicating reduced technique sensitivity and a shorter learning curve. Conclusion: Within the limitations of this ex vivo study, the loop-based retrieval technique demonstrated a higher success rate and reduced operator variability compared with the ultrasonic-only method.