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*

Background::Carotid intima-media thickness (IMT) and diameter, stiffness, and wave reflections, are independent and important clinical biomarkers and risk predictors for cardiovascular diseases. The purpose of the present study was to establish nationwide reference values of carotid properties for healthy Chinese adults and to explore potential clinical determinants.Methods::A total of 3053 healthy Han Chinese adults (1922 women) aged 18-79 years were enrolled at 28 collaborating tertiary centers throughout China between April 2021 and July 2022. The real-time tracking of common carotid artery walls was achieved by the radio frequency (RF) ultrasound system. The IMT, diameter, compliance coefficient, β stiffness, local pulse wave velocity (PWV), local systolic blood pressure, augmented pressure (AP), and augmentation index (AIx) were then automatically measured and reported. Data were stratified by age groups and sex. The relationships between age and carotid property parameters were analyzed by Jonckheere-Terpstra test and simple linear regressions. The major clinical determinants of carotid properties were identified by Pearson’s correlation, multiple linear regression, and analyses of covariance.Results::All the parameters of carotid properties demonstrated significantly age-related trajectories. Women showed thinner IMT, smaller carotid diameter, larger AP, and AIx than men. The β stiffness and PWV were significantly higher in men than women before forties, but the differences reversed after that. The increase rate of carotid IMT (5.5 μm/year in women and 5.8 μm/year in men) and diameter (0.03 mm/year in both men and women) were similar between men and women. For the stiffness and wave reflections, women showed significantly larger age-related variations than men as demonstrated by steeper regression slopes (all P for age by sex interaction <0.05). The blood pressures, body mass index (BMI), and triglyceride levels were identified as major clinical determinants of carotid properties with adjustment of age and sex. Conclusions::The age- and sex-specific reference values of carotid properties measured by RF ultrasound for healthy Chinese adults were established. The blood pressures, BMI, and triglyceride levels should be considered for clinical application of corresponding reference values.

Objective:To develop and evaluate a nomogram prediction model for poor outcome in patients with minor acute ischemic stroke (MIS) at 90 days after onset.Methods:Patients with MIS admitted to the Second People's Hospital of Hefei from January 2022 to June 2023 were retrospectively enrolled. At 90 days after onset, the modified Rankin Scale was used for outcome evaluation. <2 points were defined as good outcome and ≥2 points were defined as poor outcome. Multivariate logistic regression analysis was used to identify independent risk factors for poor outcome, and a nomogram prediction model was developed based on these factors. Results:A total of 177 patients with MIS were included, of which 61 (34.46%) had poor outcome. Multivariate logistic regression analysis showed that hypertension (odds ratio [ OR] 3.484, 95% confidence interval [ CI] 1.378-8.810; P=0.008), diabetes ( OR 2.936, 95% CI 1.301-6.625; P=0.009), National Institutes of Health Stroke Scale (NIHSS) score at admission ( OR 2.936, 95% CI 1.027-1.709; P=0.031) and systolic blood pressure at admission ( OR 1.083, 95% CI 1.053-1.115; P<0.001) were the independent risk factors for poor outcome. The established nomogram prediction model had a C-index of 0.828 and the area under the curve was 0.841 (95% CI 0.778-0.891). The calibration curve fitted well with the ideal curve. The clinical decision curve showed that the model had stronger clinical applicability. Conclusions:Hypertension, diabetes, NIHSS score and systolic blood pressure at admission are independent risk factors for poor outcome of patients with MIS. The nomogram based on the above factors has higher discriminative power and clinical value for predicting poor outcome in patients with MIS.

Post-stroke depression (PSD) is an important mental complication of stroke, affecting nearly 1/3 of stroke patients, seriously affecting patients' functional recovery and quality of life, and is associated with increased mortality of stroke patients. Traditional antidepressant treatments include medication and psychotherapy, but there may be problems with adverse reactions, tolerance, or limited effectiveness. Repetitive transcranial magnetic stimulation (rTMS), as a non-invasive neuroregulatory technique, offers a new treatment option for patients with PSD. This article reviews the application of rTMS in the treatment of PSD and its possible mechanism.

Purpose Early diagnosis of Alzheimer's disease is lack of objective imaging marker.This study evaluates characteristics of cerebral blood flow (CBF) and gray matter atrophy in patients with mild Alzheimer's disease (AD) by using 3D arterial spin labeling (3D ASL) and thin slice 3D T1 weighted images of voxel-based method (VBM).Materials and Methods Sixteen mild AD patients (mild AD group) and sixteen normal control subjects (control group) were recruited.3D ASL and T1WI SPGR sequences were performed.By using voxel-based method,the whole brain CBF and T1WI images were analyzed.CBF and volume of gray matter were compared between two groups,and correlation analysis was done.Results Compared with control group,CBF hypoperfusion was detected in bilateral precuneus,cunei,middle temporal cortex,superior temporalcortex,left parahippocampal gyrus,left superior temporal pole and right superioroccipital gyrus in mild AD group (t=3.84,Pcorrected＜0.05).Compared with control group,gray matter atrophy was found in bilateral hippocampi,amygdalae,superior temporal pole,left parahippocampal gyrus,left inferior temporal cortex in mild AD group (t=4.12,Pcorrected＜0.05).There was a correlation in left parahippocampal gyrus and left upper pole of the temporal between changes of CBF and volume of gray matter in mild AD patients (r=0.50,P＜0.05).Conclusion Voxel-based VBM and ASL can evaluate AD patients' cerebral atrophy and CBF change in early stage,and there is a correlation between changes of CBF and gray matter atrophy in some overlap areas.