1.Finite element analysis of implants with different crown-to-implant ratios under different bone conditions
Zirui KANG ; Yang WU ; Hailong SONG ; Qiaoyun YANG ; Lixiang ZANG ; Dongliang XU
Chinese Journal of Tissue Engineering Research 2026;30(2):319-328
BACKGROUND:Clinical studies suggest that both bone quality and excessive crown-to-implant ratio are factors that affect the success rate of implant surgery,but there is no consensus on how large the crown-to-implant ratio under each bone quality will affect the prognosis of implant repair.OBJECTIVE:To analyze the stress and strain of bone tissue around implant restorations with different crown-to-implant ratios under different bone types after stress loading using three-dimensional finite element method.Combined with the Frost bone mechanics regulation system theory,the physiological limits of bone strain were observed for each bone type within a certain range of crown to implant ratios.METHODS:Cone beam CT data were selected from a patient to establish solid bone block models with four different bone types(class Ⅰ bone:cortical bone thickness 3 mm+dense cancellous bone,class Ⅱ bone:cortical bone thickness 2 mm+relatively dense cancellous bone,class Ⅲ bone:cortical bone thickness 1 mm+relatively low-density cancellous bone,class Ⅳ bone:cortical bone thickness 1 mm+low-density cancellous bone).Implant restorations with five different crown-to-implant ratios(1,1.5,2,2.5,and 3)were created on each bone block model,for a total of 20 models.Vertical and oblique forces were applied to the dental crown to observe the von Mises stress values,strains,and displacement of the cortical and cancellous bones,as well as the degree of implant displacement.RESULTS AND CONCLUSION:(1)In the class Ⅰ bone model,when the crown-to-implant ratio reached 3 under oblique loading,the cortical bone strain exceeded the physiological limit.In the class Ⅱ bone model,under oblique loading,when the crown-to-implant ratio reached 2.5,the cortical bone strain exceeded the physiological limit.In the class Ⅲ bone model,under oblique loading,cortical bone exceeded the physiological limit when the crown-to-implant ratio reached 2.5,while cancellous bone reached the critical physiological limit at 1.In the class Ⅳ bone model,under oblique loading,when the crown-to-implant ratio reached 1.5,2,2.5,and 3,the cortical bone strain exceeded the physiological limit.In the class Ⅳ bone model,all five crown-to-implant ratios of cancellous bone exceeded physiological limits.(2)Under vertical load,the cancellous bone strain exceeded the physiological limit when the crown-root ratio reached 1,2,2.5,and 3 in the class Ⅲ bone model,and when the cancellous bone strain of the five crown-root ratios in the class Ⅳ bone model exceeded the physiological limit.(3)Under oblique or vertical load,the implant displacement of the 20 groups of models did not exceed 100 μm.(4)From the perspective of biomechanics,when patients with insufficient bone height choose implant restoration,the crown-root ratio that class Ⅰ bone can tolerate is up to 2.5 times,the crown-root ratio that class Ⅱ bone can tolerate is up to 2 times,and the crown-root ratio that class Ⅲ and class Ⅳ bones can tolerate is up to 1 times due to excessive strain of cancellous bone;but the crown-root ratio that cortical bone in class Ⅲ bone can tolerate is up to 2 times.Whether class Ⅲ bone can tolerate implant restoration with a high crown-root ratio and whether cancellous bone can tolerate higher strains needs further study.
2.Finite element analysis of implants with different crown-to-implant ratios under different bone conditions
Zirui KANG ; Yang WU ; Hailong SONG ; Qiaoyun YANG ; Lixiang ZANG ; Dongliang XU
Chinese Journal of Tissue Engineering Research 2026;30(2):319-328
BACKGROUND:Clinical studies suggest that both bone quality and excessive crown-to-implant ratio are factors that affect the success rate of implant surgery,but there is no consensus on how large the crown-to-implant ratio under each bone quality will affect the prognosis of implant repair.OBJECTIVE:To analyze the stress and strain of bone tissue around implant restorations with different crown-to-implant ratios under different bone types after stress loading using three-dimensional finite element method.Combined with the Frost bone mechanics regulation system theory,the physiological limits of bone strain were observed for each bone type within a certain range of crown to implant ratios.METHODS:Cone beam CT data were selected from a patient to establish solid bone block models with four different bone types(class Ⅰ bone:cortical bone thickness 3 mm+dense cancellous bone,class Ⅱ bone:cortical bone thickness 2 mm+relatively dense cancellous bone,class Ⅲ bone:cortical bone thickness 1 mm+relatively low-density cancellous bone,class Ⅳ bone:cortical bone thickness 1 mm+low-density cancellous bone).Implant restorations with five different crown-to-implant ratios(1,1.5,2,2.5,and 3)were created on each bone block model,for a total of 20 models.Vertical and oblique forces were applied to the dental crown to observe the von Mises stress values,strains,and displacement of the cortical and cancellous bones,as well as the degree of implant displacement.RESULTS AND CONCLUSION:(1)In the class Ⅰ bone model,when the crown-to-implant ratio reached 3 under oblique loading,the cortical bone strain exceeded the physiological limit.In the class Ⅱ bone model,under oblique loading,when the crown-to-implant ratio reached 2.5,the cortical bone strain exceeded the physiological limit.In the class Ⅲ bone model,under oblique loading,cortical bone exceeded the physiological limit when the crown-to-implant ratio reached 2.5,while cancellous bone reached the critical physiological limit at 1.In the class Ⅳ bone model,under oblique loading,when the crown-to-implant ratio reached 1.5,2,2.5,and 3,the cortical bone strain exceeded the physiological limit.In the class Ⅳ bone model,all five crown-to-implant ratios of cancellous bone exceeded physiological limits.(2)Under vertical load,the cancellous bone strain exceeded the physiological limit when the crown-root ratio reached 1,2,2.5,and 3 in the class Ⅲ bone model,and when the cancellous bone strain of the five crown-root ratios in the class Ⅳ bone model exceeded the physiological limit.(3)Under oblique or vertical load,the implant displacement of the 20 groups of models did not exceed 100 μm.(4)From the perspective of biomechanics,when patients with insufficient bone height choose implant restoration,the crown-root ratio that class Ⅰ bone can tolerate is up to 2.5 times,the crown-root ratio that class Ⅱ bone can tolerate is up to 2 times,and the crown-root ratio that class Ⅲ and class Ⅳ bones can tolerate is up to 1 times due to excessive strain of cancellous bone;but the crown-root ratio that cortical bone in class Ⅲ bone can tolerate is up to 2 times.Whether class Ⅲ bone can tolerate implant restoration with a high crown-root ratio and whether cancellous bone can tolerate higher strains needs further study.
3.Consistency of MSCT 3D processing technique and QCT in measuring BMD for lumbar vertebra
Xiangming LI ; Lixin ZHANG ; Weifeng WANG ; Yaqun KONG ; Chensi XU ; Wanbo ZHOU ; Shunsheng AI ; Lixiang SONG ; Yantao NIU
China Medical Equipment 2025;22(4):28-33
Objective:To study the consistency between post-processing bone mineral density(BMD)values of multi-slice spiral computed tomography(MSCT)scan and the BMD value of quantitative computed tomography(QCT)for lumbar vertebra,so as to explore the feasibility of utilizing MSCT scan-based post-processing BMD values for lumbar vertebra in clinical practice.Methods:The MSCT equipment and QCT equipment were respectively adopted to conduct imaging scan for the L2-L4 of lumber vertebra of QRM-ESP145 European Spine Phantom(ESP),and L2-L4 of lumbar vertebra of adult sheep,and L2-L4 of lumbar vertebra of adult volunteer.The L2-L4 of ESP lumber vertebra and L2-L4 of lumbar vertebra of adult sheep were scanned respectively MSCT and QCT for three times,so as to measure BMD values.The L2-L4 of lumbar vertebrae of volunteers were scanned respectively by the two methods for one time according to the standard of clinical examination,which were reconstructed by three times so as to obtain mean of them.The BMD values of QCT scan were set as control group,and the BMD values of MSCT scan were set as experiment group.The experiment group was further divided into experiment 1 group[two dimension(2D)regional volumetric BMD values of the lumbar vertebra]and experiment 2 group[three dimension(3D)global volumetric BMD post-processing of the lumbar vertebra]according to the reliability of experiment.Then,the consistency between the MSCT 3D post-processing BMD values of three groups and QCT-measured BMD values was compared and analyzed.Results:The MSCT 3D post-processing BMD values of L2-L4 of ESP lumbar vertebra of three groups were respectively(120.83±0.97),(199.57±0.54)and(119.19±1.04)mg/cm3,and that of L2-L4 of lumbar vertebra of adult sheep of three groups were respectively(414.89±1.72),(410.50±0.77)and(420.25±2.71)mg/cm3,and that of L2-L4 of lumbar vertebra of volunteer were respectively(141.22±0.09),(137.38±0.37)and(152.03±1.03)mg/cm3.There were not statistically significant differences in BMD values between MSCT examination and QCT examination(P>0.05).Conclusion:MSCT 3D post-processing BMD values on lumbar vertebra has high consistency with that of QCT measurements,which post-processing technique can replace QCT to conduct BMD examination,and reduce unnecessary radiation exposure and examination costs for patients.
4.Economic Analysis of the Collaborative Diagnosis and Treatment between Traditional Chinese Medicine and Western Medicine in the Context of High-Quality Development Strategy
Qiu ZHANG ; Qiushi REN ; Guanglian LUO ; Manxin PENG ; Jingyi XU ; Heng MA ; Lixiang ZHAI
Chinese Health Economics 2025;44(6):28-31
Collaborative diagnosis and treatment between Traditional Chinese Medicine(TCM)and Western Medicine,as an important measure for the modernization and innovation of TCM,faces great challenges such as inadequate medical resource supply and supply-demand imbalance in the context of high-quality development strategy.Supply-demand analysis and the input-output framework of modern economic theory were applied to systematically analyze the operational status of collaborative diagnosis and treatment of TCM and Western Medicine in China,and explore the intrinsic economic mechanism of its development.Furthermore,in line with the concept of the"Three Medical Synergistic Collaborations",it proposes policy recommendations from the dimension of medical care,medical insurance,and medicine.
5.Association between serum non-HDL-C and cardiovascular disease mortality risk
Baocheng DONG ; Longfei MAO ; Haitao WEI ; Shuxia ZHU ; Xiangping TANG ; Liuting XU ; Lixiang CHAI ; Yelu RUAN ; Shunqin HUANG ; Jianbing WANG
Chinese Journal of Preventive Medicine 2025;59(10):1763-1769
To analyze the relationship between serum non-HDL-C levels and cardiovascular disease (CVD) mortality in community populations. A retrospective cohort study was conducted using the Yuecheng District Health Information Platform in Shaoxing City, Zhejiang Province. The study cohort included individuals aged 40 years or older with no prior history of CVD who underwent physical examinations at Yuecheng District healthcare institutions between January and December 2019. A total of 39 038 participants were included, including 19 085 males (48.9%) and 19 953 females (51.1%), with a mean age of (73.64±9.10) years. The mean follow-up duration was 52.3 months. During follow-up, 1 227 CVD death events occurred. The results indicated a significant overall association between non-HDL-C levels and the risk of CVD mortality, including coronary heart disease (CHD) and stroke. Cox models indicated that, using the ideal level of non-HDL-C as the reference, the hazard ratios (HRs) for risk of CVD death in the suitable level, borderline elevated level and elevated level groups were 1.24 (95% CI: 1.08-1.42), 1.57 (95% CI: 1.34-1.85) and 2.31 (95% CI: 1.87-2.86), respectively. The corresponding HRs for CHD death were 1.39 (95% CI: 1.10-1.76), 1.69 (95% CI: 1.28-2.12) and 2.53 (95% CI: 1.76-3.64), respectively. Subgroup analysis revealed significant interaction effects between non-HDL-C and sex, smoking, alcohol consumption, and diabetes (all P interaction<0.05). Sensitivity analyses confirmed that results were consistent with the primary findings regarding the association between non-HDL-C and CVD mortality risk. In conclusion, increasing non-HDL-C levels are associated with higher risks of death from cardiovascular diseases, including stroke and CHD. The risk of CVD death associated with elevated non-HDL-C is greater among males, individuals with a history of diabetes, smokers or drinkers. In the future, attention should be paid to the monitoring of non-HDL-C in community health management, and the intensive and personalized management of blood lipids in high-risk population should be strengthened.
6.Effect of 3% diquafosol sodium eye drops on the tear film homeostasis of patients wearing orthokeratology lenses
Jiahong HAN ; Jianjun LIU ; Qinbin BAO ; Xu YANG
International Eye Science 2025;25(10):1667-1671
AIM:To investigate the effect of 3% diquafosol sodium eye drops on tear film homeostasis in patients wearing overnight orthokeratology lenses.METHODS:Retrospective study. A total of 340 patients(564 eyes)fitted with night-worn orthokeratology lenses from June to December 2022 were respectively divided into a diquafosol sodium group(200 cases, 323 eyes, treated with 3% diquafosol sodium eye drops)and a sodium hyaluronate group(140 cases, 241 eyes, treated with sodium hyaluronate eye drops). The uncorrected visual acuity(LogMAR), ocular surface disease index(OSDI), non-invasive tear film break-up time(NIBUT), meibomian gland infrared imaging score, and corneal epithelial fluorescein staining were analyzed and compared between the two groups.RESULTS:Compared to baseline, both groups showed significant improvements in uncorrected visual acuity(LogMAR)at 1 wk, 1, and 3 mo after lens wear(all P<0.01). However, no statistically significant difference in uncorrected visual acuity(LogMAR)was observed between the two groups at any time point(all P>0.05). No significant differences in NIBUT or OSDI scores were found between the groups before and at 1 wk after lens wear(all P>0.05). At the 1- and 3 mo follow-ups, the 3% diquafosol sodium group demonstrated significantly longer NIBUT(all P<0.001)and lower OSDI scores(all P<0.001)compared to the sodium hyaluronate group. After wearing lens for 3 mo, the meibomian gland infrared imaging scores were significantly better in the diquafosol sodium group(P<0.001), whereas no significant intergroup difference was observed in corneal fluorescein staining(P>0.05). Furthermore, the incidence of adverse events during the study period did not differ significantly between the two groups(P>0.05).CONCLUSION:Compared with sodium hyaluronate, 3% diquafosol sodium eye drops were more effective in maintaining tear film homeostasis in patients wearing overnight orthokeratology lenses.
7.Effect of silicate bioactive glass fiber on properties of calcium phosphate bone cement
Yuzheng LU ; Yingjie XIONG ; Yanbo SHAN ; Jianting YE ; Yanbin WU ; Jipeng SONG ; Yao ZHANG ; Wancheng LIN ; Qirui WENG ; Xuan CHENG ; Haoye MENG ; Wenjing XU ; Jiang PENG ; Lixiang DING
Chinese Journal of Tissue Engineering Research 2025;29(28):5994-6002
BACKGROUND:The development of calcium phosphate bone cement is limited due to its poor mechanical properties and weak osteogenic ability.Silicate bioactive glass is highly favored due to its excellent biological activity and osteogenic ability.Simultaneously,fiber structures can enhance the mechanical strength of materials.OBJECTIVE:To investigate the mechanical properties,biocompatibility,and osteogenic effect of silicate bioactive glass fiber composite calcium phosphate bone cement.METHODS:Different mass percentages(0%,10%,and 20%)of silicate bioactive glass fiber were added to the solid phase of calcium phosphate bone cement,mixed with the liquid phase and cured for 48 hours to obtain silicate bioactive glass fiber composite calcium phosphate bone cement.The mechanical properties,setting time,and ion precipitation of the cement were characterized.The three groups of bone cement extracts were co-cultured with MC3T3-E1 cells.The cell compatibility of the materials was evaluated by CCK-8 assay,live/dead staining,and phalloidin staining.After osteogenic induction,the osteogenic induction ability of the materials was evaluated by alkaline phosphatase staining,alizarin red staining,RUNX2 immunofluorescence staining,and RT-PCR.RESULTS AND CONCLUSION:(1)With the increase of silicate bioactive glass fiber content,the compressive strength and flexural strength of bone cement increased,and the setting time was prolonged.When bone cement was immersed in simulated body fluid,the precipitation of silicon ions,calcium ions,and phosphorus ions could be detected.Moreover,with the increase of silicate bioactive glass fiber content,the mass concentration of silicon ions and phosphorus ions released by bone cement increased,and the mass concentration of calcium ions decreased.(2)Live/dead staining and phalloidin staining results exhibited that silicate bioactive glass fiber composite calcium phosphate bone cement had no toxic effect on MC3T3-E1 cells.CCK-8 assay results showed that silicate bioactive glass fiber composite calcium phosphate bone cement could promote the proliferation of MC3T3-E1 cells.(3)With the increase of silicate bioactive glass fiber content in bone cement,the alkaline phosphatase activity and extracellular calcium deposition of MC3T3-E1 cells increased,the expression of RUNX2 protein increased,and the expression of alkaline phosphatase,osteocalcin,osteopontin,and RUNX2 mRNA expression increased.(4)The results indicate that silicate bioactive glass fibers can enhance the mechanical properties and osteogenic induction ability of calcium phosphate bone cement,among which 20%silicate bioactive glass fibers have a more obvious effect.
8.Unlocking the role of wound microbiome in diabetic, burn, and germ-free wound repair treated by natural and synthetic scaffolds.
Zeyu XU ; Lixiang ZHANG ; Qinghan TANG ; Chenxi YANG ; Xiaotong DING ; Ziyu WANG ; Rizhong HUANG ; Ruihan JIANG ; Joannake MAITZ ; Huaikai SHI ; Xin YAN ; Mei DONG ; Jun CHEN ; Yiwei WANG
Acta Pharmaceutica Sinica B 2025;15(1):611-626
In current clinical practice, various dermal templates and skin substitutes are used to enhance wound healing. However, the role of wound commensal microbiome in regulating scaffold performance and the healing process remains unclear. In this study, we investigated the influence of both natural and synthetic scaffolds on the wound commensal microbiome and wound repair in three distinct models including diabetic wounds, burn injuries, and germ-free (GF) wounds. Remarkably, synthetic electrospun polycaprolactone (PCL) scaffolds were observed to positively promote microbiome diversity, leading to enhanced diabetic wound healing compared to the natural scaffolds Integra® (INT) and MatriDerm® (MAD). In contrast, both natural and synthetic scaffolds exhibited comparable effects on the diversity of the microbiome and the healing of burn injuries. In GF wounds with no detectable microorganisms, a reversed healing rate was noted showing natural scaffold (MAD) accelerated wound repair compared to the open or the synthetic scaffold (PCL) treatment. Furthermore, the response of the wound commensal microbiome to PCL scaffolds appears pivotal in promoting anti-inflammatory factors during diabetic wound healing. Our results emphasize that the wound commensal microbiome, mediated by different scaffolds plays an important role in the wound healing process.
9.Aging Inhibits Memory Immune Response of CD8+T Cells in Lungs of C57BL/6J Mice Against Influenza A(H1N1)Virus
Chao WANG ; Shun LI ; Xiaonan REN ; Hua YANG ; Lixiang CHEN ; Chunhua XU ; Xiaohui ZHOU
Laboratory Animal and Comparative Medicine 2025;45(5):515-523
Objective To compare functional differences of CD8+T cells in lung tissues between young and aged C57BL/6J mice during the contraction phase and memory immune response phase after infection with influenza A(H1N1)virus.Methods Lung tissues from young(3-month-old)and aged(24-month-old)C57BL/6J female mice without influenza virus infection were collected to prepare single-cell suspensions,which were stimulated with phorbol 12-myristate 13-acetate(PMA)/ionomycin or cluster of differentiation(CD)3/CD28 antibodies(T-cell antigen receptor/co-stimulatory signals)respectively(non-specific antigens stimulation).Flow cytometry intracellular cytokine staining(ICS)was performed on lung CD8+T cells to detect their secretion capacity of tumor necrosis factor-α(TNF-α)and interferon-γ(IFN-γ).Young and aged C57BL/6J mice were infected intranasally with 490 PFU PR8 influenza virus,and reinfected with homologous influenza virus 28 days later.Lung tissues were isolated on day 28(the contraction phase)and day 32(the memory immune response phase)after primary infection.Influenza virus-specific MHC-Ⅰ tetramer staining was used to detect the proportion of virus-specific CD8+T cells in lung tissue CD8+T cells,and ICS was used to analyze TNF-α,IFN-γ,and granzyme B expression in CD8+CD44high T cell subset.Results After non-specific antigen stimulation,TNF-α and IFN-γ secretion capacity in lung tissue CD8+T cells of aged group mice was significantly higher than that of young group(P<0.05).After virus-specific antigen stimulation,there were no statistically significant differences in the proportion of virus-specific CD8+T cells and the expression levels of TNF-α,IFN-γ,and granzyme B between the two groups of mice during the contraction phase(P>0.05),while during the memory immune response phase,the proportion of virus-specific CD8+T cells and the expression levels of TNF-α,IFN-γ,and granzyme B in the aged group mice were significantly lower than those in the young group(P<0.05).Conclusion CD8+T cells in aged mice maintain normal immune-related factor expression function under non-specific antigen stimulation,but show impaired immune-related factor expression function during antigen-specific memory immune response phase,suggesting that aging leads to defects in the formation or maintenance of CD8+T cell immune memory.
10.Comparative study of fecal SDC2,ADHFE1,and PPP2R5C gene methylation detection and fecal occult blood test in colorectal cancer screening
Juan FENG ; Liyu LIN ; Xueyun YE ; Yongtao WU ; Fengxin WU ; Lizhu XU ; Lixiang ZHOU
China Journal of Endoscopy 2025;31(7):31-36
Objective To compare the colonoscopy results of patients with positive fecal SDC2,ADHFE1,and PPP2R5C gene methylation tests to those with positive fecal occult blood tests,and analyze the effectiveness of colorectal cancer(CRC)screening.This study aims to provide a scientific basis for risk assessment in CRC screening.Methods From December 2023 to May 2024,9 284 combined test kits for SDC2,ADHFE1,and PPP2R5C gene methylation were distributed to high-risk individuals aged 40~80 years.Among them,841 patients(9.1%)tested positive.These patients were encouraged via telephone to undergo colonoscopy,with colonoscopy combined with pathological diagnosis as the gold standard,a total of 495 positive patients completed electronic colonoscopy.Among them,the 251 patients who tested positive for fecal SDC2,ADHFE1,and PPP2R5C gene methylation and completed electronic colonoscopy were the observation group;concurrently,244 patients who tested positive for fecal occult blood tests and underwent electronic colonoscopy were selected as the control group.Compare two groups of patients with polyp,number,shape,pathological changes and pathological types.Results There was no statistically significant difference in number and lesion location of polyps between the two groups of patients(P>0.05).The proportion of Yamada type Ⅰ in the observation group was lower than that in the control group,while the proportion of Yamada type Ⅱ was higher than that in the control group.The difference was statistically significant(P<0.05).In the observation group,1 case(0.4%)of CRC,62 cases(24.7%)of advanced adenomas,78 cases(31.1%)of non-advanced adenomas,20 cases(8.0%)of hyperplastic polyps,and 90 cases(35.9%)with no dysplastic lesions were identified.In the control group,6 cases(2.5%)of CRC,38 cases(15.6%)of advanced adenomas,53 cases(21.7%)of non-advanced adenomas,19 cases(7.8%)of hyperplastic polyps,and 128 cases(52.5%)with no dysplastic lesions were identified.The proportions of non-advanced adenomas and advanced adenomas were lower in the control group than those in the observation group,while the no dysplastic lesions rate was higher in the control group,the differences were statistically significant(P<0.05).Conclusion The detection rate of colorectal non-advanced adenomas and advanced adenomas is higher with fecal SDC2,ADHFE1,and PPP2R5C gene methylation testing compared to the fecal occult blood test.

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