Instrument separation is a critical complication during root canal therapy, impacting treatment success and long-term tooth preservation. The etiology of instrument separation is multifactorial, involving the intricate anatomy of the root canal system, instrument-related factors, and instrumentation techniques. Instrument separation can hinder thorough cleaning, shaping, and obturation of the root canal, posing challenges to successful treatment outcomes. Although retrieval of separated instrument is often feasible, it carries risks including perforation, excessive removal of tooth structure and root fractures. Effective management of separated instruments requires a comprehensive understanding of the contributing factors, meticulous preoperative assessment, and precise evaluation of the retrieval difficulty. The application of appropriate retrieval techniques is essential to minimize complications and optimize clinical outcomes. The current manuscript provides a framework for understanding the causes, risk factors, and clinical management principles of instrument separation. By integrating effective strategies, endodontists can enhance decision-making, improve endodontic treatment success and ensure the preservation of natural dentition.
Humans ; Root Canal Therapy/adverse effects* ; Consensus ; Root Canal Preparation/adverse effects*

Objective To explore the method to reconstruct finger tip. Methods Transplanted the big toe tip to reconstruct the finger tip and anastomosed the artery and nerve of big toe with the artery and nerve of the finger.The venae digitales plantares of finger,toe and venae digitales volares of finger and toe were anastomosed with microsurgery. Results All the reconstituted finger tips were successful.The shape of the reconstituted finger tips were near to the normal finger tip.The shape of the big toes had only a little change. Conclusion Use the big toe tip can reconstruct a beautiful finger tip look like the normal finger.