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 pharmacokinetic characteristics of sufentanil in individuals with normal body mass index(BMI),overweight BMI,and different CYP3A4/5 enzyme genotypes.Methods The patients receiving laparoscopic surgery under general anesthesia in the First Affiliated Hospital of Army Medical University from November 2020 to September 2021 were prospectively recruited in this study.Before the operation,the oral swabs were collected from all the patients for genotyping using the human CYP3A4/5 gene kit.Based on the potential impact of combination of their polymorphisms on sufentanil metabolism and the proportion of different genotype combinations of CYP3A4/5 enzymes,the patients were divided into groups I(3A4 homozygous mutation or 3A4 heterozygous mutation+3A5 homozygous mutation),II(3A4 heterozygous mutation+3A5 heterozygous mutation),and III(3A4 wild type or 3A4 heterozygous mutation+3A5 wild type).According to their BMI,they were also assigned into a normal body weight group(18.5～24.0 kg/m2)and an overweight group(24～<28 kg/m2),and the differences in drug metabolism parameters were statistically analyze between the 2 groups.After routine general anesthesia induction(sufentanil 0.5 μg/kg),venous blood samples were collected to detect the changes in its concentration using high performance liquid chromatography-mass spectrometry(HPLC-MS).The pharmacokinetic data of sufentanil were calculated between the normal BMI group and overweight group in all participants and between the 2 body weight groups among those with different genotype combinations.Results Among the 90 participants completing the blood drug concentration test,8 patients had their blood samples contaminated(including 1 case with an anesthesia duration of<2 h),and 3 were excluded due to low weight or overweight.Eventually,79 participants were included in the pharmacokinetic analysis on the normal body weight group and the overweight group.Compared with the normal body weight group,the central compartment volume of distribution in the overweight group was significantly reduced(P<0.05),while no obvious differences were observed between the 2 groups in terms of peripheral compartment volume of distribution,total clearance rate,peripheral compartment clearance rate,distribution half-life,clearance half-life,and area under the blood concentration-time curve.In group Ⅰ(n=26),the overweight patients(n=13)had significantly reduced central compartment volume of distribution,peripheral compartment volume of distribution,and peripheral compartment clearance rate when compared with the normal body weight patients(n=13)(P<0.05),while no differences were observed in other pharmacokinetic parameters.In groups Ⅱ(n=25)and Ⅲ(n=28),the overweight patients and normal body weight patients had no statistical differences in all pharmacokinetic parameters.Conclusion Among the patients with the same genotype combination of CYP3A4/5 mutations,there was no difference in the metabolism of sufentanil between the overweight and normal weight patients.Additionally,in the population of 3A4 homozygous mutation or 3A4 heterozygous mutation+3A5 homozygous mutation,the overweight patients have smaller peripheral distribution range of sufentanil,and weakened metabolic process.

Objective To develop an unmanned aerial vehicle (UAV)-borne radiation monitoring system with high detection efficiency and nuclide identification ability for airborne monitoring in nuclear emergency. Methods The UAV-borne CeBr₃ radiation monitoring system was composed of four cerium bromide (CeBr₃) crystal detectors coupled with silicon photomultipliers (SiPMs) and other components including integrated modules, intelligent electronic devices, and new composite materials. Results According to various performance tests on the system, the crystal energy resolution was better than 5% (@0.662 MeV), the peak drift of the energy spectrum was within ±1 channel, the linear fit of energy was 0.99997, the change in the count rate of each energy window during 12 h long-term measurement was less than 5%, and the detection efficiency was higher compared with that of NaI (Tl) detectors of the same volume. Conclusion Through ground point source testing and theoretical calculation, the system has reliable ability to identify radionuclides, which can be used in nuclide identification and the preparedness and response for nuclear and radiation emergencies.

The dental operative microscope has been widely employed in the field of dentistry, particularly in endodontics and operative dentistry, resulting in significant advancements in the effectiveness of root canal therapy, endodontic surgery, and dental restoration. However, the improper use of this microscope continues to be common in clinical settings, primarily due to operators' insufficient understanding and proficiency in both the features and established operating procedures of this equipment. In October 2019, Professor Jingping Liang, Vice Chairman of the Society of Cariology and Endodontology, Chinese Stomatological Association, organized a consensus meeting with Chinese experts in endodontics and operative dentistry. The objective of this meeting was to establish a standard operation procedure for the dental operative microscope. Subsequently, a consensus was reached and officially issued. Over the span of about four years, the content of this consensus has been further developed and improved through practical experience.
Humans ; Dentistry, Operative ; Consensus ; Endodontics ; Root Canal Therapy ; Dental Care

Objective    To compare clinical effects of enlarged thymectomy for the treatment of myasthenia gravis (MG) complicated with thymoma via subxiphoid and subcostal arch thoracoscopic resection versus median sternotomy resection. Methods    We retrospectively analyzed the clinical data of patients with MG complicated with thymoma admitted in Tangdu Hospital of the Air Force Military Medical University between December 2011 and December 2021. Patients who underwent subxiphoid and subcostal arch thoracoscopic enlarged thymectomy were allocated to a SR group, and patients who underwent median sternotomy enlarged thymectomy were allocated to a MR group. Perioperative outcomes were compared between the two groups. Results    A total of 456 patients were collected. There were 51 patients in the MR group, including 30 males and 21 females aged 23-66 (49.5±11.8) years. There were 405 patients in the SR group, among whom 51 patients were matched to the MR group by propensity score matching, including 28 males and 23 females aged 26-70 (47.2±12.2) years. The operations were accomplished successfully in all patients, and no conversion to thoracotomy occurred in the SR group. The SR group had advantages in the operation time, intraoperative blood loss,  chest drainage duration, hospital stay time, patients’ satisfaction level, pain score and complications (all P<0.05). No statistical difference was found in the number of intraoperative lymph node dissection stations, number of intraoperative lymph nodes dissected or remission of MG between the two groups (P>0.05). Conclusion    Subxiphoid and subcostal arch thoracoscopic enlarged thymectomy and lymphadenectomy is a safe, effective and feasible minimally invasive procedure for the treatment of MG complicated with thymoma.

Objective    To compare clinical effects of extended thymectomy for the treatment of thymic abnormalities with myasthenia gravis (MG) between subxiphoid and subcostal arch thoracoscopic resection (SR) and the unilateral thoracoscopic resection (UR) by a propensity-score matching analysis. Methods    We retrospectively analyzed the clinical data of 612 patients who presented with MG and were admitted to Tangdu Hospital of Air Force Military Medical University between December 2011 and December 2018. Of these patients, 520 patients underwent subxiphoid and subcostal arch thoracoscopic extended thymectomy (a SR group) and 92 unilateral thoracoscopic extended thymectomy (a UR group). Ninety-two patients in the SR group were matched with the UR group by propensity-score matching analysis. There were 52 males and 40 females with an average age of 26-70 (50.2±10.3) years in the SR group, and 47 males and 45 females with an average age of 20-73 (51.5±12.1) years in the UR group. The operation time, intraoperative blood loss, thoracic drainage time, postoperative hospital stay, thorough adipose tissue removal, postoperative remission of MG, patients’ satisfaction score, pain and complications were compared and analyzed between the two groups. Results    All operations were accomplished successfully, without conversion to thoracotomy of the two groups. There were statistical differences between the two groups in operation time (46.2±19.5 min vs. 53.4±23.5 min), chest drainage duration (0 d vs. 3.4±1.2 d), hospital stay (2.9±1.9 d vs. 3.6±1.7 d), patients’ satisfaction score (7.9±2.1 points vs. 6.7±1.2 points) and pain scores (all P<0.05). There were no statistical differences between the two groups in intraoperative blood loss (52.2±12.7 mL vs. 51.2±10.3 mL), peripheral adipose tissue removal (8.1±0.6 vs. 7.9±0.9), remission rate of MG (89.1% vs. 85.9%) and rate of postoperative complications (10.9% vs. 6.5%) (all P>0.05). Conclusion    Subxiphoid and subcostal arch thoracoscopic extended thymectomy is a safe and feasible minimally invasive procedure for the management of MG with thymic abnormalities.