1.Mechanism of Yishen Huoxue Tongqiao Formula in Improving Unilateral Vestibular Labyrinth Destruction by Regulating Metabolism-neuroplasticity
Yu TIAN ; Hui LENG ; Rupeng QU ; Xianglong HAO ; Aiping WANG ; Lei SHI ; Zhongyuan QU ; Ye DONG ; Xiande MA ; Yangling HUANG
Chinese Journal of Experimental Traditional Medical Formulae 2026;32(5):54-64
ObjectiveThis study aims to explore the mechanism by which Yishen Huoxue Tongqiao Formula improves metabolism-neuroplasticity and treats unilateral vestibular labyrinth destruction by regulating the metabolic balance of glutamate (Glu)/γ-aminobutyric acid (GABA). Methods48 Sprague-Dawley (SD) adult rats were randomly divided into the sham operation group, model group, Yishen Huoxue Tongqiao Formula groups with low, medium, and high doses (9.20, 18.39, 36.78 g·kg-1), and betahistine group (1.62 mg·kg-1). A unilateral vestibular labyrinth destruction (vestibular dysfunction) model was established by intratympanic injection of chloroform into the right ear, while the control group received intratympanic injection of normal saline. Drugs were administered once daily for seven consecutive days. During the period, behavioral tests were performed to evaluate the behaviors of rats after unilateral vestibular labyrinth destruction. Hematoxylin-eosin (HE) staining and Nissl staining were used to observe the neuronal morphology in the medial vestibular nucleus. Golgi staining was employed to assess the number of dendritic spines of neurons in the medial vestibular nucleus. Ultra-performance liquid chromatography-tandem mass spectrometry (LC-ESI-MS/MS) was utilized to detect Glu/GABA. Immunofluorescence and immunohistochemistry were used to detect the expressions of neuronal nuclei (NeuN), growth-associated protein 43 (GAP-43), and glial fibrillary acidic protein (GFAP). Western blot and real-time fluorescent quantitative polymerase chain reaction (Real-time PCR) were applied to determine the expressions of glutamate-immunoreactive (Glu-IR), GABA, GFAP, postsynaptic density protein 95 (PSD-95), and GAP-43. ResultsCompared with the sham operation group, the model group presented with head deviation, balance disorder, increased tail suspension score, nuclear consolidation of medial vestibular nerve neurons, and decreased Nissl bodies (P<0.01). The number of dendritic spines in neurons and NeuN-positive cells decreased. The content of Glu decreased. The content of GABA increased (Glu/GABA decreased). The expression of GAP-43 was down-regulated, and GFAP was up-regulated (P<0.05, P<0.01). The expressions of Glu-IR, PSD-95, and GAP-43 proteins, as well as Glu-IR mRNA decreased, while the expressions of GABA and GFAP proteins and mRNA increased (P<0.05, P<0.01). Compared with those in the model group, the head deviation, imbalanced behavior, and tail suspension scores in each treatment group decreased, with alleviated neuronal injury and recovered Nissl bodies (P<0.01). The number of dendritic spines of neurons increased, and the number of NeuN-positive cells rebounded. The content of Glu increased, and the content of GABA decreased (Glu/GABA increased). GFAP was down-regulated, and GAP-43 was up-regulated (P<0.05, P<0.01). The expressions of Glu-IR, PMD-95, and GAP-43 proteins, as well as Glu-IR mRNA increased, while the expressions of GABA and GFAP proteins and mRNA decreased. The effect was more significant in the high-dose group (P<0.01). ConclusionThe Yishen Huoxue Tongqiao Formula can alleviate vestibular dysfunction, and its mechanism may be associated with regulating the metabolic balance of Glu/GABA, mitigating neural damage, improving synaptic plasticity (promoting GAP-43 expression and inhibiting GFAP expression), and facilitating vestibular compensation.
2.Spectrum-effect Relationship of Bupleuri Radix Processed with Trionyx sinensis Blood for Yin Deficiency Based on Saponins
Mengyu HOU ; Xia ZHAO ; Zhiyu GUO ; Ting LIU ; Yuexing MA ; Yaohui YE
Chinese Journal of Experimental Traditional Medical Formulae 2025;31(3):147-155
ObjectiveTo analyze the pharmacodynamic activity of Bupleuri Radix processed with Trionyx sinensis blood in the treatment of Yin deficiency and study the spectrum-effect relationship of this medicine. MethodsHigh performance liquid chromatography was employed to establish the fingerprints of 15 batches of Bupleuri Radix processed with Trionyx sinensis blood, and the similarity was evaluated according to the SOP of Similarity Evaluation System of Chromatographic Fingerprint of TCM (version 2012). A mouse model of Yin deficiency induced by thyroxine was established. The relationship between the active components and the effect on Yin deficiency was explored by grey correlation analysis and partial least squares method based on the changes in the serum levels of triiodothyronine (T3), thyroxine (T4), cyclic adenosine phosphate (cAMP), and cyclic guanosine phosphate (cGMP). The components screened out based on the spectrum-effect relationship were used for retrieval of the targets from the Traditional Chinese Medicine Systems Pharmacology and Analysis Database (TCMSP), The Encyclopedia of Traditional Chinese Medicine (ETCM), and Integrative Pharmacology-based Research Platform of Traditional Chinese Medicine (TCMIP). Furthermore, the Online Mendelian Inheritance in Man (OMIM), GeneCards, TTD, DisGeNET, and Drugbank were employed to establish the active component-target against Yin deficiency network of Bupleuri Radix processed with Trionyx sinensis blood. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses were carried out for the core targets. Real-time PCR was conducted to verify the predicted key pathways and mechanisms. ResultsThe fingerprints of the 15 batches of Bupleuri Radix processed with Trionyx sinensis blood showed the similarities of 0.976-0.999 with the control fingerprint. Compared with the model group, the drug administration group showed elevated levels of T3 and T4 and lowered levels of cAMP, cGMP and cAMP/cGMP. The results of grey correlation analysis showed that active components in terms of the correlations followed the trend of saikosaponin B1 > saikosaponin B2 > saikosaponin C > saikosaponin D > saikosaponin A. The partial least squares analysis showed that saikosaponins A, D, B1, and B2 had higher VIP values. Network pharmacology predicted a total of 30 common targets, which were enriched in 276 GO terns and 115 KEGG pathways. The results of Real-time PCR showed that the model group had lower mRNA levels of Caspase-9, kinase insert domain receptor (KDR), and mammalian target of rapamycin (mTOR) and higher mRNA level of mouse double minute 2 homolog (MDM2) than the blank group and the drug administration group. ConclusionBupleuri Radix processed with Trionyx sinensis blood has therapeutic effect on Yin deficiency syndrome, which provides a new idea for studying Bupleuri Radix processed with Trionyx sinensis blood.
3.Evaluation of nutritional value of three kinds of medicinal snakes based on content of 15 amino acids.
Xi WANG ; Ye-Yuan LIN ; Wen-Ting ZHONG ; Zhi-Guo MA ; Meng-Hua WU ; Hui CAO ; Ying ZHANG
China Journal of Chinese Materia Medica 2025;50(9):2411-2421
A high-performance liquid chromatography method using pre-column derivatization with 6-aminoquinolyl-N-hydroxysuccinimidyl carbamate was developed to determine the content of 15 amino acids in the medicinal snakes Bungarus Parvus, Agkistrodon, and Zaocys. The results showed that the total amino acid(TAA) content ranged from 277.13 to 515.05 mg·g~(-1), with the top four amino acids in all three species being glutamic acid(Glu), glycine(Gly), aspartic acid(Asp), and lysine(Lys). The essential amino acid(EAA) content ranged from 74.56 to 203.94 mg·g~(-1), with Agkistrodon exhibiting the highest content. The non-essential amino acid(NEAA), semi-essential amino acid(semi-EAA), and medicinal amino acid(MAA) content ranged from 189.06 to 318.23, 12.89 to 33.53, and 179.83 to 342.33 mg·g~(-1), respectively, with Zaocys having the highest content in these categories. Amino acid nutritional value was evaluated using the amino acid ratio(RAA), amino acid ratio coefficient(RCAA), and amino acid ratio coefficient score(SRCAA), and the results indicated that all three medicinal snakes possessed good nutritional value. The amino acid composition was similar across the species, though significant differences in content were observed. Based on these differences, an orthogonal partial least squares-discriminant analysis(OPLS-DA) model was established, which could clearly distinguish between the three medicinal snake species. The key differences in amino acid content included Gly, tyrosine(Tyr), Glu, and serine(Ser), which may be related to the observed clinical application differences among the species. Further research into the mechanisms of these differential amino acids is expected to provide more insights into the clinical application disparities of these three medicinal snake species.
Amino Acids/chemistry*
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Animals
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Nutritive Value
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Chromatography, High Pressure Liquid
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Snakes/classification*
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Bungarus
4.Evidence evaluation of 12 commonly-used Chinese patent medicines in treatment of osteoporosis based on Eff-iEC and GRADE.
Guang-Cheng WEI ; Zhi-Long ZHANG ; Xin-Wen ZHANG ; Ye LUO ; Jin-Jie SHI ; Rui MA ; Jie-Yang DU ; Ke ZHU ; Jiu-Cheng PENG ; Yu-Long YA ; Wei CAO
China Journal of Chinese Materia Medica 2025;50(15):4372-4385
This study applied the grading of recommendations assessment, development and evaluation(GRADE) system and the integrated evidence chain-based effectiveness evaluation of traditional Chinese medicine(Eff-iEC) to evaluate the evidence for 12 commonly used Chinese patent medicines for the treatment of osteoporosis, which are frequently recommended in guidelines or expert consensuses. The results showed that Xianling Gubao Capsules/Tablets were rated as C(low-level evidence) according to the GRADE system, and as BA~+B~+(intermediate evidence) according to the Eff-iEC system. Jintiange Capsules were rated as C(low-level evidence) by the GRADE system, and as AA~+B(high-level evidence) by the Eff-iEC system. Gushukang Granules/Capsules were rated as C(low-level evidence) by GRADE system, and as BA~+B~+(intermediate evidence) by Eff-iEC system. Zuogui Pills were rated as C(low-level evidence) by GRADE system, and as AA~(++)B~+(high-level evidence) by Eff-iEC system. Qianggu Capsules were rated as D(extremely low-level evidence) by GRADE system, and as AA~+B~+(high-level evidence) by Eff-iEC system. Zhuanggu Zhitong Capsules were rated as D(extremely low-level evidence) by GRADE system, and as BA~+B(intermediate evidence) by Eff-iEC system. Jingui Shenqi Pills were rated as D(extremely low-level evidence) by GRADE system, and as AA~+B(high-level evidence) by Eff-iEC system. Quanduzhong Capsules were rated as D(extremely low-level evidence) by GRADE system, and as AD~+B~+(low-level evidence) by Eff-iEC system. Epimedium Total Flavones Capsules were rated as D(extremely low-level evidence) by GRADE system, and as AAB~+(high-level evidence) by Eff-iEC system. Yougui Pills were rated as D(extremely low-level evidence) by GRADE system, and as AA~(++)B~(+ )(high-level evidence) by Eff-iEC system. Qigu Capsules were rated as D(extremely low-level evidence) by GRADE system, and as BB~+B(intermediate evidence) by Eff-iEC system. Liuwei Dihuang Pills were rated as C(low-level evidence) by GRADE system, and as AA~(++)B~+(high-level evidence) by Eff-iEC system. Overall, the Eff-iEC system provides a more comprehensive assessment of the effectiveness evidence for traditional Chinese medicine(TCM) than the GRADE system. However, it still has certain limitations that hinder its wider promotion and application. In terms of clinical evidence evaluation, both the Eff-iEC and GRADE systems reflect that the current clinical research quality on Chinese patent medicines for the treatment of osteoporosis is generally low. High-quality clinical trials are still needed in the future to further validate clinical efficacy.
Drugs, Chinese Herbal/therapeutic use*
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Osteoporosis/drug therapy*
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Humans
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Nonprescription Drugs/therapeutic use*
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Evidence-Based Medicine
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Medicine, Chinese Traditional
5.Expert consensus on the diagnosis and treatment of cemental tear.
Ye LIANG ; Hongrui LIU ; Chengjia XIE ; Yang YU ; Jinlong SHAO ; Chunxu LV ; Wenyan KANG ; Fuhua YAN ; Yaping PAN ; Faming CHEN ; Yan XU ; Zuomin WANG ; Yao SUN ; Ang LI ; Lili CHEN ; Qingxian LUAN ; Chuanjiang ZHAO ; Zhengguo CAO ; Yi LIU ; Jiang SUN ; Zhongchen SONG ; Lei ZHAO ; Li LIN ; Peihui DING ; Weilian SUN ; Jun WANG ; Jiang LIN ; Guangxun ZHU ; Qi ZHANG ; Lijun LUO ; Jiayin DENG ; Yihuai PAN ; Jin ZHAO ; Aimei SONG ; Hongmei GUO ; Jin ZHANG ; Pingping CUI ; Song GE ; Rui ZHANG ; Xiuyun REN ; Shengbin HUANG ; Xi WEI ; Lihong QIU ; Jing DENG ; Keqing PAN ; Dandan MA ; Hongyu ZHAO ; Dong CHEN ; Liangjun ZHONG ; Gang DING ; Wu CHEN ; Quanchen XU ; Xiaoyu SUN ; Lingqian DU ; Ling LI ; Yijia WANG ; Xiaoyuan LI ; Qiang CHEN ; Hui WANG ; Zheng ZHANG ; Mengmeng LIU ; Chengfei ZHANG ; Xuedong ZHOU ; Shaohua GE
International Journal of Oral Science 2025;17(1):61-61
Cemental tear is a rare and indetectable condition unless obvious clinical signs present with the involvement of surrounding periodontal and periapical tissues. Due to its clinical manifestations similar to common dental issues, such as vertical root fracture, primary endodontic diseases, and periodontal diseases, as well as the low awareness of cemental tear for clinicians, misdiagnosis often occurs. The critical principle for cemental tear treatment is to remove torn fragments, and overlooking fragments leads to futile therapy, which could deteriorate the conditions of the affected teeth. Therefore, accurate diagnosis and subsequent appropriate interventions are vital for managing cemental tear. Novel diagnostic tools, including cone-beam computed tomography (CBCT), microscopes, and enamel matrix derivatives, have improved early detection and management, enhancing tooth retention. The implementation of standardized diagnostic criteria and treatment protocols, combined with improved clinical awareness among dental professionals, serves to mitigate risks of diagnostic errors and suboptimal therapeutic interventions. This expert consensus reviewed the epidemiology, pathogenesis, potential predisposing factors, clinical manifestations, diagnosis, differential diagnosis, treatment, and prognosis of cemental tear, aiming to provide a clinical guideline and facilitate clinicians to have a better understanding of cemental tear.
Humans
;
Dental Cementum/injuries*
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Consensus
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Diagnosis, Differential
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Cone-Beam Computed Tomography
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Tooth Fractures/therapy*
6.Ursodeoxycholic acid inhibits the uptake of cystine through SLC7A11 and impairs de novo synthesis of glutathione.
Fu'an XIE ; Yujia NIU ; Xiaobing CHEN ; Xu KONG ; Guangting YAN ; Aobo ZHUANG ; Xi LI ; Lanlan LIAN ; Dongmei QIN ; Quan ZHANG ; Ruyi ZHANG ; Kunrong YANG ; Xiaogang XIA ; Kun CHEN ; Mengmeng XIAO ; Chunkang YANG ; Ting WU ; Ye SHEN ; Chundong YU ; Chenghua LUO ; Shu-Hai LIN ; Wengang LI
Journal of Pharmaceutical Analysis 2025;15(1):101068-101068
Ursodeoxycholic acid (UDCA) is a naturally occurring, low-toxicity, and hydrophilic bile acid (BA) in the human body that is converted by intestinal flora using primary BA. Solute carrier family 7 member 11 (SLC7A11) functions to uptake extracellular cystine in exchange for glutamate, and is highly expressed in a variety of human cancers. Retroperitoneal liposarcoma (RLPS) refers to liposarcoma originating from the retroperitoneal area. Lipidomics analysis revealed that UDCA was one of the most significantly downregulated metabolites in sera of RLPS patients compared with healthy subjects. The augmentation of UDCA concentration (≥25 μg/mL) demonstrated a suppressive effect on the proliferation of liposarcoma cells. [15N2]-cystine and [13C5]-glutamine isotope tracing revealed that UDCA impairs cystine uptake and glutathione (GSH) synthesis. Mechanistically, UDCA binds to the cystine transporter SLC7A11 to inhibit cystine uptake and impair GSH de novo synthesis, leading to reactive oxygen species (ROS) accumulation and mitochondrial oxidative damage. Furthermore, UDCA can promote the anti-cancer effects of ferroptosis inducers (Erastin, RSL3), the murine double minute 2 (MDM2) inhibitors (Nutlin 3a, RG7112), cyclin dependent kinase 4 (CDK4) inhibitor (Abemaciclib), and glutaminase inhibitor (CB839). Together, UDCA functions as a cystine exchange factor that binds to SLC7A11 for antitumor activity, and SLC7A11 is not only a new transporter for BA but also a clinically applicable target for UDCA. More importantly, in combination with other antitumor chemotherapy or physiotherapy treatments, UDCA may provide effective and promising treatment strategies for RLPS or other types of tumors in a ROS-dependent manner.
7.Butyrate-based ionic liquid for improved oral bioavailability and synergistic anti-colorectal cancer activity of glycyrol.
Ziyu WANG ; Xingyue SHI ; Yikang SHU ; Ran GAO ; Ting SUN ; Mingyue WU ; Mingxin DONG ; Weiguo WU ; Ruili MA ; Daoquan TANG ; Min YE ; Shuai JI
Journal of Pharmaceutical Analysis 2025;15(11):101359-101359
Image 1.
8.Identification and Potential Clinical Utility of Common Genetic Variants in Gestational Diabetes among Chinese Pregnant Women
Claudia Ha-ting TAM ; Ying WANG ; Chi Chiu WANG ; Lai Yuk YUEN ; Cadmon King-poo LIM ; Junhong LENG ; Ling WU ; Alex Chi-wai NG ; Yong HOU ; Kit Ying TSOI ; Hui WANG ; Risa OZAKI ; Albert Martin LI ; Qingqing WANG ; Juliana Chung-ngor CHAN ; Yan Chou YE ; Wing Hung TAM ; Xilin YANG ; Ronald Ching-wan MA
Diabetes & Metabolism Journal 2025;49(1):128-143
Background:
The genetic basis for hyperglycaemia in pregnancy remain unclear. This study aimed to uncover the genetic determinants of gestational diabetes mellitus (GDM) and investigate their applications.
Methods:
We performed a meta-analysis of genome-wide association studies (GWAS) for GDM in Chinese women (464 cases and 1,217 controls), followed by de novo replications in an independent Chinese cohort (564 cases and 572 controls) and in silico replication in European (12,332 cases and 131,109 controls) and multi-ethnic populations (5,485 cases and 347,856 controls). A polygenic risk score (PRS) was derived based on the identified variants.
Results:
Using the genome-wide scan and candidate gene approaches, we identified four susceptibility loci for GDM. These included three previously reported loci for GDM and type 2 diabetes mellitus (T2DM) at MTNR1B (rs7945617, odds ratio [OR], 1.64; 95% confidence interval [CI],1.38 to 1.96]), CDKAL1 (rs7754840, OR, 1.33; 95% CI, 1.13 to 1.58), and INS-IGF2-KCNQ1 (rs2237897, OR, 1.48; 95% CI, 1.23 to 1.79), as well as a novel genome-wide significant locus near TBR1-SLC4A10 (rs117781972, OR, 2.05; 95% CI, 1.61 to 2.62; Pmeta=7.6×10-9), which has not been previously reported in GWAS for T2DM or glycaemic traits. Moreover, we found that women with a high PRS (top quintile) had over threefold (95% CI, 2.30 to 4.09; Pmeta=3.1×10-14) and 71% (95% CI, 1.08 to 2.71; P=0.0220) higher risk for GDM and abnormal glucose tolerance post-pregnancy, respectively, compared to other individuals.
Conclusion
Our results indicate that the genetic architecture of glucose metabolism exhibits both similarities and differences between the pregnant and non-pregnant states. Integrating genetic information can facilitate identification of pregnant women at a higher risk of developing GDM or later diabetes.
9.Identification and Potential Clinical Utility of Common Genetic Variants in Gestational Diabetes among Chinese Pregnant Women
Claudia Ha-ting TAM ; Ying WANG ; Chi Chiu WANG ; Lai Yuk YUEN ; Cadmon King-poo LIM ; Junhong LENG ; Ling WU ; Alex Chi-wai NG ; Yong HOU ; Kit Ying TSOI ; Hui WANG ; Risa OZAKI ; Albert Martin LI ; Qingqing WANG ; Juliana Chung-ngor CHAN ; Yan Chou YE ; Wing Hung TAM ; Xilin YANG ; Ronald Ching-wan MA
Diabetes & Metabolism Journal 2025;49(1):128-143
Background:
The genetic basis for hyperglycaemia in pregnancy remain unclear. This study aimed to uncover the genetic determinants of gestational diabetes mellitus (GDM) and investigate their applications.
Methods:
We performed a meta-analysis of genome-wide association studies (GWAS) for GDM in Chinese women (464 cases and 1,217 controls), followed by de novo replications in an independent Chinese cohort (564 cases and 572 controls) and in silico replication in European (12,332 cases and 131,109 controls) and multi-ethnic populations (5,485 cases and 347,856 controls). A polygenic risk score (PRS) was derived based on the identified variants.
Results:
Using the genome-wide scan and candidate gene approaches, we identified four susceptibility loci for GDM. These included three previously reported loci for GDM and type 2 diabetes mellitus (T2DM) at MTNR1B (rs7945617, odds ratio [OR], 1.64; 95% confidence interval [CI],1.38 to 1.96]), CDKAL1 (rs7754840, OR, 1.33; 95% CI, 1.13 to 1.58), and INS-IGF2-KCNQ1 (rs2237897, OR, 1.48; 95% CI, 1.23 to 1.79), as well as a novel genome-wide significant locus near TBR1-SLC4A10 (rs117781972, OR, 2.05; 95% CI, 1.61 to 2.62; Pmeta=7.6×10-9), which has not been previously reported in GWAS for T2DM or glycaemic traits. Moreover, we found that women with a high PRS (top quintile) had over threefold (95% CI, 2.30 to 4.09; Pmeta=3.1×10-14) and 71% (95% CI, 1.08 to 2.71; P=0.0220) higher risk for GDM and abnormal glucose tolerance post-pregnancy, respectively, compared to other individuals.
Conclusion
Our results indicate that the genetic architecture of glucose metabolism exhibits both similarities and differences between the pregnant and non-pregnant states. Integrating genetic information can facilitate identification of pregnant women at a higher risk of developing GDM or later diabetes.
10.Finite element analysis of various root shield thicknesses in maxillary central incisor socket-shield technique
Guangneng CHEN ; Siyang LUO ; Mei WANG ; Bin YE ; Jiawen CHEN ; Yin LIU ; Yuwen ZUO ; Xianyu HE ; Jiajin SHEN ; Minxian MA
Chinese Journal of Tissue Engineering Research 2025;29(10):2052-2060
BACKGROUND:Socket-shield technique can effectively maintain labial soft and hard tissues,but the incidence of postoperative complications such as exposure and displacement of root shield is relatively high.It is speculated that the root shield may be exposed and displaced due to excessive load after long-term function of dental implants. OBJECTIVE:Through three-dimensional finite element analysis,we aim to study the influence of varying root shield thicknesses on the stress distribution,equivalent stress peaks,and displacement in the root shield,periodontal ligaments,implant,and surrounding alveolar bone under normal occlusal loading.We also attempt to analyze the correlation between the thickness of the root shield and occurrence of mechanical events such as root shield exposure,displacement,and fracture. METHODS:Cone-beam CT data of a patient who met the indication standard of socket-shield technique for maxillary central incisor were retrieved from database.Reverse engineering techniques were used to build models of the maxillary bone and root shield,while forward engineering was used to create models for the implant components based on their parameters.Models depicting various root shield thicknesses(0.5,1.0,1.5,and 2.0 mm)were created using Solidworks 2022 software.ANSYS Workbench 2021 software was then used to simulate and analyze the effects of varying root shield thicknesses on stress distribution,equivalent stress peaks,and displacement of the root shields,periodontal ligaments,implants,and surrounding alveolar bone under normal occlusion. RESULTS AND CONCLUSION:(1)In all root shield models,the stress was concentrated on the palatal cervical side,both sides of the edges and the lower edge of the labial side.As the thickness of the root shield increased,the equivalent stress peak and displacement showed a decreasing trend.The 0.5 mm thickness model produced a stress concentration of 176.20 MPa,which exceeded the yield strength(150 MPa)of tooth tissue.(2)The periodontal ligament stress in each group was concentrated in the neck margin and upper region.With the increase of root shield thickness,the equivalent stress peak and displacement of periodontal ligament showed a decreasing trend.(3)Implant stress in all models was concentrated in the neck of the implant and the joint of the implant-repair abutment,and the labial side was more concentrated than the palatal side.With the increase of root shield thickness,the equivalent stress peak of the implant in the model showed an increasing trend.(4)In each group of models,stress of cortical bone concentrated around the neck of the implant and the periphery of the root shield,and the labial side was more concentrated than the palatal side.With the increase of the thickness of the root shield,the equivalent stress peak around the root shield decreased;the peak value of the equivalent stress of the bone around the neck of the implant showed an increasing trend.In the model,the stress of cancellous bone was mainly concentrated around the neck of the lip of the implant,the top of the thread,the root tip and the lower margin of the root shield,and the labial side was more concentrated than the palatal side.With the increase of the thickness of the root shield,the peak value of the equivalent stress of the bone around the root shield in the model showed a decreasing trend.The minimum principal stress of cortical bone in each group of models was concentrated around the neck of the implant,exhibiting a fan-shaped distribution.As the thickness of the root shield increased,the minimum principal stress of cortical bone showed an increasing trend.(5)These results indicate that different thicknesses of the root shield have different biomechanical effects.The root shield with a thickness of 0.5 mm is easy to fracture.For patients with sufficient bone width,the root shield with a thickness of 2.0 mm is an option to reduce the risk of complications such as root shield exposure,fracture,and displacement.Meanwhile,it should be taken into account to protect the periodontal ligament in the preparation process,and rounding treatments ought to be carried out on both sides and the lower edge of the root shield.

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