1.Exploring Chemical Constituent Distribution in Blood/Brain(Hippocampus) and Emotional Regulatory Effect of Raw and Vinegar-processed Products of Citri Reticulatae Pericarpium Viride
Yi BAO ; Yonggui SONG ; Qianmin LI ; Zhifu AI ; Genhua ZHU ; Ming YANG ; Huanhua XU ; Qin ZHENG ; Yiting HUANG ; Zihan GAO ; Dan SU
Chinese Journal of Experimental Traditional Medical Formulae 2026;32(2):189-197
ObjectiveTo investigate the migration and distribution characteristics of chemical constituents in blood and hippocampal tissues before and after vinegar processing of Citri Reticulatae Pericarpium Viride(CRPV), and to explore the potential material basis and mechanisms underlying their regulatory effects on emotional disorders by comparing the effects of raw and vinegar-processed products of CRPV. MethodsUltra-performance liquid chromatography-quadrupole-time-of-flight mass spectrometry(UPLC-Q-TOF-MS/MS) was employed to characterize and identify the chemical constituents of raw and vinegar-processed products of CRPV extracts, as well as their migrating components in blood and hippocampal tissues after oral administration. Reference standards, databases, and relevant literature were utilized for compound annotation, with data processing performed using PeakView 1.2 software. Seventy male C57BL/6 mice were randomly divided into seven groups, including the blank group, model group, diazepam group(2.5 mg·kg-1), raw CRPV low/high dose groups(0.6, 1.2 g·kg-1), and vinegar-processed CRPV low/high dose groups(0.6, 1.2 g·kg-1), with 10 mice per group. Except for the blank group, all other groups underwent chronic restraint stress(2 h·d-1) for 20 d. Each drug-treated group received oral administration at the predetermined dose starting 10 d after modeling, with a total treatment duration of 10 d. Following model-based drug administration, mice underwent open-field, forced swimming, and elevated plus maze tests. After anesthesia with isoflurane, whole brains were collected from each group of mice, and hippocampi were dissected. Reactive oxygen species(ROS) level in hippocampal tissues was quantified by enzyme-linked immunosorbent assay(ELISA). Hematoxylin-eosin(HE) staining was used to observe hippocampal tissue morphology. Immunofluorescence was performed to detect neuronal nuclei(NeuN) and peroxisome proliferator-activated receptor alpha(PPARα) expressions in hippocampal tissue. Then, pharmacodynamic evaluations were conducted to assess the effects of raw and vinegar-processed CRPV on mood disorders, exploring the potential mechanisms. ResultsVinegar processing caused significant changes in the chemical composition of CRPV, with 18 components showing increased relative content and 35 components showing decreased relative content. The primary changes occurred in flavonoid compounds, including 20 flavonoids, 20 flavonoid glycosides, 3 triterpenes, 3 phenolic acids, 1 alkaloid, and 6 other compounds. Twenty-one components were detected in blood(15 methoxyflavones, 4 flavonoid glycosides, and 2 phenolic acids), with 17 shared between raw and vinegar-processed CRPV. Seven components reached hippocampal tissues(all common to both forms). In regulating emotional disorders, Vinegar-processed CRPV exhibited superior antidepressant-like effects compared to raw products. HE staining revealed that both treatments improved hippocampal neuronal morphology, particularly in the damaged CA1 and CA3 regions. Immunofluorescence and ELISA analyses demonstrated that both raw and vinegar-processed CRPV significantly modulated NeuN and PPARα expressions in hippocampal tissue while alleviating oxidative stress induced by excessive ROS(P<0.05). ConclusionThe chemical composition of CRPV undergoes changes after vinegar processing, but the migrating components in blood and hippocampus are primarily methoxyflavonoids. These components may serve as the potential material basis for activating the PPARα pathway, thereby negatively regulating ROS generation in the hippocampus, reducing oxidative stress, and promoting the development of NeuN-positive neurons. These findings provide experimental evidence for enhancing quality standards, pharmacodynamic material research, and active drug development of raw and vinegar-processed CRPV.
2.Efficacy and safety of sequential or combined therapy with tenofovir alafenamide fumarate in entecavir-treated patients with low-level viremia
Yijing ZHANG ; Lingying HUANG ; Bowu CHEN ; Wanchun ZHU ; Man LI ; Jie SHEN ; Yueqiu GAO
Journal of Clinical Hepatology 2026;42(1):66-73
ObjectiveTo investigate the efficacy of sequential tenofovir alafenamide fumarate (TAF) therapy versus the regimen of entecavir (ETV) combined with TAF in chronic hepatitis B (CHB) patients experiencing low-level viremia (LLV) after ETV therapy, as well as their impact on virologic response, liver and renal function, and blood lipid levels. MethodsA total of 217 CHB patients with LLV after ETV treatment who were admitted to Shuguang Hospital Affiliated to Shanghai University of Traditional Chinese Medicine from May 2020 to December 2023 were enrolled, and according to the treatment regimen, they were divided into TAF group (180 patients receiving sequential TAF therapy) and combined group (37 patients receiving ETV+TAF therapy). The propensity score matching (PSM) method was used to match the patients at a ratio of 1∶1, and finally 37 patients were included in each group to balance the baseline confounding factors. The two groups were compared in terms of hepatitis B virus DNA (HBV DNA) clearance rate, hepatitis B envelope antigen (HBeAg) clearance rate, liver and renal function parameters (liver stiffness measurement [LSM], platelet count [PLT], aspartate aminotransferase [AST], alanine aminotransferase [ALT], and creatinine [Cr]), blood lipid levels (total cholesterol [TC], triglyceride [TG], high-density lipoprotein cholesterol [HDL-C], and low-density lipoprotein cholesterol [LDL-C]), and the incidence rate of adverse reactions. The independent samples t-test was used for comparison of normally distributed continuous data between two groups, and the paired t-test was used for comparison within each group; the chi-square test was used for comparison of categorical data between groups. ResultsAfter 48 weeks of treatment, compared with the TAF group, the combined group had significantly higher HBV DNA clearance rate (86.49% vs 59.46%, χ²=6.852, P=0.009) and HBeAg clearance rate (59.46% vs 35.14%, χ²=4.391, P=0.036). After treatment, compared with the TAF group, the combined group had significantly lower levels of LSM (7.01±1.50 kPa vs 7.90±1.68 kPa, t=2.404, P=0.019), AST (18.02±2.28 U/L vs 21.12±2.85 U/L, t=5.166, P<0.001), and ALT (19.85±3.86 U/L vs 22.00±3.90 U/L, t=2.383, P=0.020) and significantly higher levels of PLT [(218.35±42.60)×109/L vs (192.82±44.13)×109/L, t=2.532, P=0.014] and Cr (70.92±6.54 μmoL/L vs 67.60±6.13 μmoL/L, t=2.253, P=0.027). After treatment, there was a slight increase in the level of TC in both the TAF group (5.60±0.89 mmol/L vs 5.18±0.85 mmol/L, t=2.076, P=0.041) and the combined group (5.45±0.80 mmol/L vs 5.02±0.83 mmol/L, t=2.269, P=0.026). There was no significant difference in the incidence rate of adverse reactions between the TAF group and the combined group (21.62% vs 18.92%, χ²=0.084, P=0.772). ConclusionFor ETV-treated CHB patients experiencing LLV, compared with sequential TAF therapy, the ETV+TAF combined therapy can effectively increase virologic response rate, alleviate liver fibrosis, and improve liver function, whereas sequential TAF therapy has less impact on renal function. Sequential or combined therapy with TAF may induce a slight increase in the level of TC, which should be taken seriously in clinical practice.
3.Epidemiological survey of Helicobacter pylori infection and correlation of dietary and lifestyle habits among adult physical examination population in Xuzhou Area
Jiao JIAO ; Xingsong JIANG ; Chunping QIAN ; Shujuan GAO ; Shuli ZHAO ; Jie ZHUANG ; Hui ZHANG ; Yun ZHU
Journal of Public Health and Preventive Medicine 2026;37(1):163-166
Objective To explore the prevalence of Helicobacter pylori (Hp) infection and its association with dietary and lifestyle habits among the adult physical examination population in Xuzhou area. Methods Retrospectively selected the physical examination population who underwent HP testing at our hospital's physical examination center from May 2021 to December 2023 as the research object. The prevalence of Hp infection in the population was analyzed based on the physical examination results. A questionnaire survey was used to collect information on the eating and living habits of all study subjects. Logistic regression was used to analyze the relationship between eating and living habits and Hp infection. Results A total of 1 354 physical examination people were included in the study, and the Hp infection rate was 37.30% (505/1354). The difference in Hp infection rates among people of different age groups is statistically significant (P<0.05), with the middle-aged population (41-59 years old) having the highest Hp positive infection rate (45.38%).High salt (41.11%), hot diet (40.56%), history of smoking (45.23%) and drinking (43.80%), less consumption of fruits and vegetables (43.73%), irregular exercise (41.29%), irregular diet People who frequently eat out (43.56%) and eat out frequently (42.57%) have a higher Hp infection rate (P<0.05).After adjusting for demographic factors such as gender, age, place of residence and education level, multivariate Logistic regression results showed that high-salt diet (OR=3.975, 95%CI: 2.670-5.917) and hot diet (OR=3.357, 95%CI: 2.291-4.919), smoking (OR=1.458, 95%CI: 1.082-1.964), drinking alcohol (OR=1.654, 95%CI: 1.279-2.138), eating fruits and vegetables (OR=1.759, 95%CI: 1.345-2.301), regular exercise (OR=1.822, 95%CI: 1.371-2.421), regular diet (OR=1.893, 95%CI: 1.391-2.575), eating out (OR=1.690, 95%CI: 1.277-2.237) were associated with the risk of Hp infection (P<0.05). Conclusion The positive infection rate of Hp among the physical examination population in Xuzhou is slightly lower than the average epidemic level in China. Cultivating healthy eating and living habits can effectively reduce the risk of Hp infection.
4.Compound Xishu Granules Inhibit Proliferation of Hepatocellular Carcinoma Cells by Regulating Ferroptosis
Yuan TIAN ; Yuxi WANG ; Zhen LIU ; Yuncheng MA ; Hongyu ZHU ; Xiaozhu WANG ; Qian LI ; Jian GAO ; Weiling WANG ; Wenhui XU ; Ting WANG
Chinese Journal of Experimental Traditional Medical Formulae 2025;31(2):37-45
ObjectiveTo study the mechanism of compound Xishu granules (CXG) in inhibiting the proliferation of hepatocellular carcinoma cells by regulating ferroptosis. MethodsThe transplanted tumor model of human Huh7 was established with nude mice and the successfully modeled mice were randomized into model, Fufang Banmao (0.21 g·kg-1), low-dose (1.87 g·kg-1) CXG, medium-dose (3.74 g·kg-1) CXG, and high-dose (7.49 g·kg-1) CXG groups. Mice were administrated with drinking water or CXG for 28 days, and the body weight and tumor volume were measured every 4 days. Hematoxylin-eosin staining was employed to observe the histopathological changes of tumors. The cell-counting kit-8 (CCK-8) was used to examine the survival rate of Huh7 cells treated with different concentrations (0, 31.25, 62.5, 125, 250, 500, 1 000 mg·L-1) of CXG for 24 h and 48 h. CA-AM, DCFH-DA, and C11-BODIPY581/591 fluorescent probes were used to determine the intracellular levels of ferrous ion (Fe2+), reactive oxygen species (ROS), and lipid peroxide (LPO), respectively. The colorimetric method was employed to measure the levels of glutathione (GSH) and superoxide dismutase (SOD). Western blot was employed to determine the protein levels of glutathione peroxidase 4 (GPX4), transferrin receptor 1 (TFR1), and ferritin heavy chain 1 (FTH1), respectively. ResultsIn the animal experiment, compared with the model group, the drug treatment groups showed reductions in the tumor volume from day 12 (P<0.01). After treatment, the Fufang Banmao and low-, medium-, and high-dose CXG groups had lower tumor volume, relative tumor volume, and tumor weight than the model group (P<0.05), with tumor inhibition rates of 48.99%, 79.93%, 91.38%, and 97.36%, respectively. Moreover, the CXG groups had lower tumor volume and relative tumor volume (P<0.05 in all the three dose groups) and lower tumor weight (P<0.05 in medium-dose and high-dose groups) than the Fufang Banmao group. Compared with the model group, the drug treatment groups showed reduced number of tumor cells, necrotic foci with karyopyknosis, nuclear fragmentation, and nucleolysis, and the high-dose CXG group showed an increase in the proportion of interstitial fibroblasts. In the cell experiment, compared with the blank group, CXG reduced the survival rate of Huh7 cells in a dose-dependent manner after incubation for 24 h and 48 h (P<0.05). Compared with the blank group, the RSL3 group and the low-, medium-, and high-dose CXG groups showed a decrease in the relative fluorescence intensity of CA-AM and increases in the fluorescence intensity of DCFH-DA and fluorescence ratio of C11-BODIPY581/591, which indicated elevations in the levels of Fe2+ (P<0.01), ROS (P<0.05), and LPO (P<0.01), respectively. Compared with the blank group, the RSL3 and low-, medium-, and high-dose CXG groups showed lowered levels of GSH and SOD (P<0.05). In addition, the RSL3 group and the medium- and high-dose CXG groups showed down-regulated expression of GPX4 and FTH1 (P<0.05), and the low- and high-dose CXG groups presented up-regulated expression of TFR1 (P<0.05). ConclusionCXG suppresses the proliferation of hepatocellular carcinoma cells by inducing ferroptosis via downregulating the GSH-GPX4 signaling axis and increasing intracellular Fe2+and LPO levels.
5.Prevalence and influencing factors of school bullying experienced by primary and middle school students
ZHU Yunjiao ; GU Fang ; MENG Jia ; LI Juanjuan ; SHEN Yu ; GAO Lei
Journal of Preventive Medicine 2025;37(1):1-6
Objective:
To investigate the situation and influencing factors of school bullying experienced by primary and middle school students, so as to provide the basis for formulating school bullying intervention measures and promoting students' physical and mental health development.
Methods:
All the counties (cities, districts) in Zhejiang Province were stratified to urban and suburban areas, primary, junior high and senior high school students were selected using a stratified cluster sampling method. Basic information, lifestyle and school bullying were collected through questionnaire surveys. Factors affecting school bullying experienced by primary and middle school students were analyzed using a multivariable logistic regression model.
Results:
Totally 137 846 valid questionnaires were recovered, with an effective recovery rate of 97.17%. There were 72 526 males (52.61%) and 65 320 females (47.39%). There were 47 561 primary school students (34.50%), 47 701 junior high school students (34.61%) and 42 584 senior high school students (30.89%). A total of 3 987 students suffered from school bullying, accounting for 2.89%. The proportions of being maliciously teased, being intentionally excluded from group activities/isolated, being teased about physical defects or appearance, being hit/kicked/pushed/shoved/locked in a room, being threatened, and being extorted for money were 2.04%, 1.18%, 1.11%, 0.86%, 0.84% and 0.83%, respectively. Multivariable logistic regression analysis showed that the students who were males (OR=1.122, 95%CI: 1.048-1.202), lived in suburban areas (OR=1.322, 95%CI: 1.233-1.418), lived in areas with medium (OR=1.086, 95%CI: 1.006-1.173) or underdeveloped (OR=1.298, 95%CI: 1.191-1.415) economic level, had higher academic levels (junior high school, OR=1.380, 95%CI: 1.270-1.499; senior high school, OR=1.210, 95%CI: 1.083-1.351), lived on campus (OR=1.489, 95%CI: 1.372-1.616), engaged in fights (OR=6.029, 95%CI: 5.585-6.509), attempted to smoke (OR=1.320, 95%CI: 1.128-1.545), drank (OR=1.735, 95%CI: 1.575-1.912), were scolded and beaten by parents (OR=1.972, 95%CI: 1.822-2.135) and were obese (OR=1.240, 95%CI: 1.132-1.360) were more likely to experience school bullying.
Conclusion
The harm of school bullying to the physical and mental health of primary and middle school students should be taken seriously, and active policy measures should be adopted to strengthen intervention.
6.Seasonal distribution characteristics, source analysis and health risk assessment of polycyclic aromatic hydrocarbons in PM2.5 in Lianyungang City in 2019-2023
Shengnan GAO ; Jinkun LI ; Li CHEN ; Zhengdong XYU ; Hongru ZHU ; Jian WANG ; Zhiyang YAO
Journal of Public Health and Preventive Medicine 2025;36(1):65-69
Objective To study the seasonal distribution characteristics of polycyclic aromatic hydrocarbons (PAHs) in PM2.5 in Lianyungang City, and analyze the sources of PAHs pollution, and to evaluate the health risks of PAHs in different seasons. Methods PM2.5 samples were collected regularly from January 2019 to December 2023, and 16 types of PAHs were determined by HPLC. Kruskal-Wallis H test was used to compare the concentrations of PM2.5 and PAHs in different years and seasons. The source of PAHs was analyzed by characteristic ratio and principal component analysis (PCA). Health risks were assessed using the BaP equivalent method and the incremental lifetime cancer risk (ILCR) model. Results The annual exceedance rates of PM2.5 and BaP in Lianyungang showed a decreasing trend from 2019 to 2023. PM2.5, total PAHs and PAHs monomers (except Ace, Flu and Acy) all showed significant seasonal differences, with the highest concentration in winter (P<0.001). The average proportion of 4-ring PAHs was the highest and the average proportion of 2-ring PAHs was the lowest. The proportion of 5-6 ring PAHs was relatively high in winter and spring. PM2.5and PAHs were negatively correlated with temperature, relative humidity and precipitation, and were positively correlated with atmospheric pressure. PM2.5 was negatively correlated with wind speed, while some PAHs monomers were positively correlated with wind speed. The characteristic ratio and PCA results showed that the main sources of PAHs in Lianyungang City were mixed sources of road dust and vehicle emissions, oil pollution sources and biomass combustion sources. The results of ILCR showed that the highest risk was found in adults, with males slightly higher than females. In Lianyungang, the maximum value of ILCR in winter was more than 10-6 in people over 9 years old. Conclusion The main sources of PAHs in PM2.5 in Lianyungang City are mixed sources of road dust and vehicle emissions, oil pollution sources, and biomass combustion sources. Under the current exposure level of PAHs in PM2.5, residents have a certain potential carcinogenic risk.
7.Deep learning for accurate lung artery segmentation with shape-position priors
Chao GUO ; Xuehan GAO ; Qidi HU ; Jian LI ; Haixing ZHU ; Ke ZHAO ; Weipeng LIU ; Shanqing LI
Chinese Journal of Clinical Thoracic and Cardiovascular Surgery 2025;32(03):332-338
Objective To propose a lung artery segmentation method that integrates shape and position prior knowledge, aiming to solve the issues of inaccurate segmentation caused by the high similarity and small size differences between the lung arteries and surrounding tissues in CT images. Methods Based on the three-dimensional U-Net network architecture and relying on the PARSE 2022 database image data, shape and position prior knowledge was introduced to design feature extraction and fusion strategies to enhance the ability of lung artery segmentation. The data of the patients were divided into three groups: a training set, a validation set, and a test set. The performance metrics for evaluating the model included Dice Similarity Coefficient (DSC), sensitivity, accuracy, and Hausdorff distance (HD95). Results The study included lung artery imaging data from 203 patients, including 100 patients in the training set, 30 patients in the validation set, and 73 patients in the test set. Through the backbone network, a rough segmentation of the lung arteries was performed to obtain a complete vascular structure; the branch network integrating shape and position information was used to extract features of small pulmonary arteries, reducing interference from the pulmonary artery trunk and left and right pulmonary arteries. Experimental results showed that the segmentation model based on shape and position prior knowledge had a higher DSC (82.81%±3.20% vs. 80.47%±3.17% vs. 80.36%±3.43%), sensitivity (85.30%±8.04% vs. 80.95%±6.89% vs. 82.82%±7.29%), and accuracy (81.63%±7.53% vs. 81.19%±8.35% vs. 79.36%±8.98%) compared to traditional three-dimensional U-Net and V-Net methods. HD95 could reach (9.52±4.29) mm, which was 6.05 mm shorter than traditional methods, showing excellent performance in segmentation boundaries. Conclusion The lung artery segmentation method based on shape and position prior knowledge can achieve precise segmentation of lung artery vessels and has potential application value in tasks such as bronchoscopy or percutaneous puncture surgery navigation.
8.Mechanotransduction proteins in intervertebral disc degeneration
Xilin GAO ; Si WU ; Chao ZHANG ; Liguo ZHU ; Bifeng FU ; Ping WANG
Chinese Journal of Tissue Engineering Research 2025;29(3):579-589
BACKGROUND:Recent research indicates that disc degeneration is closely related to abnormal stress load,and mechanotransduction proteins play a key role in it. OBJECTIVE:To investigate the role and mechanism of mechanotransduction proteins in the mechanotransduction process induced by abnormal mechanical stimulation in disc degeneration,and to summarize the current treatment strategies targeting mechanotransduction to delay intervertebral disc degeneration. METHODS:Using"intervertebral disc,nucleus pulposus,annulus fibrosus,cartilaginous endplate,cell,mechanics,signal transduction,protein,biomechanics"as Chinese search terms,and"intervertebral disc,nucleus pulposus,annulus fibrosus,cartilaginous endplate,cell,mechanical stimulation,signal transduction,protein,biomechanics"as English search terms,relevant literature in the PubMed and CNKI databases was searched.A total of 88 articles were ultimately included for review. RESULTS AND CONCLUSION:Disc cells can sense external mechanical stimulation through various mechanotransduction proteins and convert it into biological responses within the cells.These transduction proteins mainly include collagen proteins in the extracellular matrix,cell membrane surface receptors(such as integrins and ion channels),and cytoskeleton structural proteins.Their regulation of mechanotransduction processes primarily involves the activation of multiple pathways,such as the PI3K/AKT signaling pathway,nuclear factor-kB signaling pathway,and Ca2+/Calpain2/Caspase3 pathway.Mechanotransduction proteins play a key role in the mechanotransduction of disc cells.Abnormal expression of these proteins or resulting changes in the extracellular matrix environment can disrupt the mechanical balance of disc cells,leading to disc degeneration.In-depth study of the expression and regulatory mechanisms of mechanotransduction proteins in disc cells,and identification of key pathological links and therapeutic targets,is of significant importance for developing treatment strategies for disc degeneration.Current strategies to delay intervertebral disc degeneration by targeting mechanotransduction mainly include regulation of transduction proteins and improvement of the extracellular matrix.However,research in this area is still in its early stages.As research continues,new breakthroughs are expected in the regulation of disc degeneration by mechanotransduction proteins.
9.Identification of core genes of osteoarthritis by bioinformatics
Xuekun ZHU ; Heng LIU ; Hui FENG ; Yunlong GAO ; Lei WEN ; Xiaosong CAI ; Ben ZHAO ; Min ZHONG
Chinese Journal of Tissue Engineering Research 2025;29(3):637-644
BACKGROUND:At present,osteoarthritis has become a major disease affecting the quality of life of the elderly,and the therapeutic effect is poor,often focusing on preventing the disease process,and the pathogenesis of osteoarthritis is still not fully understood.Bioinformatics analysis was carried out to explore the main pathogenesis of osteoarthritis and related mechanisms of gene coding regulation. OBJECTIVE:To screen core differential genes with a major role in osteoarthritis by gene expression profiling. METHODS:Datasets were downloaded from the Gene Expression Omnibus(GEO):GSE114007,GSE117999,and GSE129147.Differential genes in the GSE114007 and GSE117999 data collections were screened using R software,performing differential genes to weighted gene co-expression network analysis.The module genes most relevant to osteoarthritis were selected to perform protein interaction analysis.Candidate core genes were selected using the cytocape software.The candidate core genes were subsequently subjected to least absolute shrinkage and selection operator regression and COX analysis to identify the core genes with a key role in osteoarthritis.The accuracy of the core genes was validated using an external dataset,GSE129147. RESULTS AND CONCLUSION:(1)A total of 477 differential genes were identified,265 differential genes associated with osteoarthritis were obtained by weighted gene co-expression network analysis,and 8 candidate core genes were identified.The least absolute shrinkage and selection operator regression analysis finally yielded a differential gene ASPM with core value that was externally validated.(2)It is concluded that abnormal gene ASPM expression screened by bioinformatics plays a key central role in osteoarthritis.
10.Stress analysis of computer aided design/computer aided manufacture post-core materials with different elastic moduli
Liangwei XU ; Xitian TIAN ; Lin CHEN ; Hongyan GAO ; Xian ZHU ; Guican YANG ; Yinghao CHEN
Chinese Journal of Tissue Engineering Research 2025;29(10):2061-2066
BACKGROUND:Post and core restoration is a common choice for tooth defects,but the repair effects of various post and core materials are different. OBJECTIVE:To evaluate the stress distribution at the post and core,tooth root,and bonding agent site of post and core models made of different elastic modulus post and core materials using finite element method. METHODS:A three-dimensional root canal treated maxillary central incisor model was built using three-dimensional modeling software,which was restored with a full ceramic crown.The post and core materials in the restoration used nanoceramic resin(elastic modulus=12.8 GPa),composite resin(elastic modulus=16 GPa),hybrid ceramic(elastic modulus=34.7 GPa),glass ceramic(elastic modulus=95 GPa),titanium alloy(elastic modulus=112 GPa),and zirconia(elastic modulus=209.3 GPa).The model was fixed in cortical bone.A 100 N concentrated force of 45° from the long axis of the tooth was applied to 1/3 of the crown and tongue side of the central incisor.The stress distribution of the post and core,dentin,and tooth-root bonding agent in the model was repaired by the maximum principal stress criterion. RESULTS AND CONCLUSION:(1)When the post and core materials with higher elastic modulus was used,the post-core stress in the repair model was more concentrated.When the elastic modulus of the post and core materials(nanoceramic resin and composite resin)was close to dentin,the stress distribution of the post and core was more uniform.The stress distribution of dentin in all restoration models was similar regardless of post and core materials.When the post and core with higher elastic modulus was used,more stress concentration was shown at the post and root bonding agent in the repair model.(2)The maximum stress values at the post and core,tooth root,and the bonding agent site of post and tooth root in the nanoceramic resin model were 31.00,33.21,and 0.51 MPa,respectively.The maximum stress values at the post and core,tooth root,and the bonding agent between the post and tooth root in the composite resin model were 36.84,33.14,and 0.59 MPa,respectively.In the mixed ceramic model,the maximum stress values at the post and core,tooth root,and the bonding agent between the post and tooth root were 64.05,32.83,and 1.00 MPa,respectively.In the glass ceramic model,the maximum stress values at the post and core,tooth root,and the bonding agent between the post and tooth root were 112.30,32.69,and 1.73 MPa,respectively.In the titanium alloy model,the maximum stress values of the post and core,tooth root,and the bonding agent between the post and tooth root were 120.00,32.17,and 1.86 MPa,respectively.In the zirconia model,the maximum stress values of the post and core,tooth root,and the bonding agent between the post and tooth root were 148.80,31.85,and 2.28 MPa,respectively.(3)The higher the elastic modulus of the post and core material,the higher the maximum stress at the post and core during restoration.The elastic modulus of the post and core material had no significant effect on the maximum stress of the dental bonding agent and dentin.


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