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*

Osteoporosis （OP） and osteoarthritis （OA） are common bone diseases in clinic. OP is a systemic skeletal disease， and OA is a chronic degenerative joint disease with high prevalence and disability rates. With the advent of the aging population， the incidence rate of OA and OP is increasing year by year， and they have become common diseases of the elderly. The quality of life and physical and mental health of patients are severely affected by the above two bone diseases. Chinese medicine has a long history of treating bone diseases， with a good clinical effect on preventing and treating OP， OA， and other bone diseases with few side effects. It is one of the commonly used methods to treat bone diseases. Polysaccharides， as one of the active substances of Chinese medicine， have various pharmacological activities and a wide range of sources with low toxicity， and their effect cannot be ignored. The role of polysaccharides in the treatment of bone diseases has been deeply studied. It has been found that the mechanism of Chinese medicine polysaccharides in treating OP and OA involves multiple levels， targets， and pathways. Through the analysis and summary of the relevant literature on the mechanism of Chinese medicine polysaccharides in treating OP and OA， it was found that Chinese medicine polysaccharides mainly treated OP by regulating the bone dynamic balance between osteoblasts and osteoclasts and affecting bone marrow mesenchymal stem cells and bone microstructure. The mechanism of Chinese medicine polysaccharides in the treatment of OA is related to the regulation of chondrocyte growth， the increase in the proteoglycan and collagen content in the cartilage matrix， and the reduction of oxygen free radical content and inflammatory mediator level. This study aimed to further explore the internal relationship among mechanisms of Chinese medicine polysaccharides in the treatment of bone diseases， to provide relevant ideas for the study of Chinese medicine polysaccharides in the treatment of bone diseases.