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.

3T3-L1 adipocytes were cultured with various concentrations of high-density lipoprotein ( HDL, 0, 10, 50, and 100 μg/ml ) for 16 h and with lipopolysaccharide ( LPS, 100 ng/ml ) for another 6 h. Interleukin-8 in the medium was determined by ELISA, and PPAR-γ mRNA expression by reverse transacription polymerase chain reaction (RT-PCR). Interleukin-8 levels were increased in LPS-treated cells ( P＜0.05 ), but decreased in HDL-treated cells in the dose-dependent manner. PPARγ mRNA expressions were increased in HDL-treated groups than those treated only with LPS. These results suggested HDL may decrease interleukin-8 secretion via up-regulating PPARγ expression in adipocytes.

Aim To explore the effect of high density lipoprotein and apolipoprotein A-I mimetic peptide on the secretion and the expression of adiponectin in fully differentiated 3T3-L1 adipocytes in inflammatory status and the possible mechanism.Methods Fully differentiated 3T3-L1 adipocytes were incubated in the medium containing various concentrations of high density lipoprotein(10~100 mg?L-1) and apolipoprotein A-I mimetic peptide(1~50 mg?L-1)with 100 ?g?L-1 lipopolysaccharide(n=3).Evaluate the levels of adiponectin in supernatant,the mRNA expression of adiponectin and PPAR?,and the activity of NF-?B.Results During LPS stimulation adiponectin concentrations in supernatant decreased from 0.25?0.03 ?g?L-1 to 0.14?0.02 ?g?L-1(P