检索结果-南通市图书馆

Analysis of the stress Distribution Pattern of Anatomic and Non-Anatomic Tooth Forms on Maxillary and Mandibular Edentulous Ridges—A Photoelastic study

引用

Journal of Biosciences and Medicines 2020年第6期8卷 113-126页

作者： T. K. Chandr.thara M. Lovely Eldo koshy Jitendr. Jethwani Department of Prosthodontics Sri Sankara Dental College Trivandrum India Department of Prosthodontics Ras Al-Khaimah College of Dental Sciences Ras Al Khaimah UAE dr. koshy’s dental clinic Cochin India school of Dentistry Virginia Commonwealth University Richmond VA USA

Aim: To compare the type of stress distribution pattern occurring with anatomic and non-anatomic tooth forms beneath a complete denture in both maxillary and mandibular arch. Methodology: A photoelastic model of the e... 详细信息

strong>Aim: strong>To compare the type of stress distribution pattern occurring with anatomic and non-anatomic tooth forms beneath a complete denture in both maxillary and mandibular arch. strong>Methodology: strong>A photoelastic model of the edentulous maxillary and mandibular ridge was prepared meticulously to simulate the human mandible and maxilla. Two sets of acrylic teeth with anatomic and non-anatomic occlusal forms were used to fabricate upper and lower dentures. A vertical static load of 100 N was applied through the mandibular model to the maxillary model. After load application on the dentures the photoelastic model as well as the upper and lower complete dentures were sectioned in the midline. The sectioned photoelastic model was viewed through a polariscope to observe the fringe pattern indicating varying amounts of stress distribution. In this study, a two-dimensional photoelastic stress analysis technique was utilized. strong>Results:strong> Force per unit area was observed more in anatomic teeth than the non-anatomic counterpart. Hence anatomic tooth forms may increase the possibility of bone resorption rate over a period of time. However, in non-anatomic lower teeth, a decrease in value was observed from posterior to anterior region. strong>Conclusion: strong>stress of greater magnitude was observed with cuspal teeth whereas non-anatomic (0°) showed slightly less magnitude of stress. Depending upon the clinical situation the clinician needs to choose the type of occlusal tooth forms for edentulous patients.

关键词： Complete Denture Anatomic Tooth Forms Non Anatomic Tooth Forms stress Distribution Photoelastic study

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Correlation between Maxillary Central Incisor Crown Form and Maxillary dental Arch Form:A Model‑Based Morphometric,Cross‑sectional study

引用

Journal of Forensic science and Medicine 2018年第2期4卷 70-75页

作者： Jayasankar Purushothaman Pillai Riddhi Amrutbhai Patel Alka M Banker J Rajarajeswari Department of Oral Pathology Government Dental College and HospitalAhmedabad Consultant dental surgeon Shraddha Orthodontic ClinicBharuch Department of Orthodontia Goenka Research Institute of Dental Science Consultant dental surgeon Sai Balaji Dental ClinicGandhinagarGujaratIndia

The crown form of maxillary central incisor tooth is one of the vital phenomenon for a person’s *** crown form has been compared with other anatomical parameters such as arch form and facial *** different classes of tooth forms which relate to square,tapered,and ovoid forms are *** aim of this study was to morphometrically evaluate the correlation between maxillary dental arch form and the maxillary central incisor crown *** cast models of fifty male and fifty female normal occlusion controls in the age group of 18-23 years were *** mesiodistal(MD)dimensions of the maxillary central incisors were measured at incisal(MD_I)and at gingival(MD_G)*** transverse widths of maxillary casts were measured at the first molar and at the first premolar *** measured data were statistically analyzed using the sPss *** MD dimensions of maxillary central incisor were significantly greater in males than *** ratio between the two MD dimensions also varied significantly among *** intermolar width(IMW)and interfirst premolar width(IPmW)between males and females were highly significant(Ps the ratio between these two parameters in males and females was not significant(P=0.43).Eighty‑eight percentage of the participants were found to have an ovoid type of maxillary arch,while only 45%of them had the ovoid form of maxillary central *** MD_I and the IMW were found to be in the ratio of 1:5.5 in both *** MD_G and the IPmW were in the ratio of 1:4.7 in males and 1:4.5 in *** was a weak positive correlation between MD_I and IMW(r^(2)=0.146)and between MD_G and IPmW(r^(2)=0.05).No significant concordance between the maxillary central incisor crown form and the maxillary arch form was found in this study.

关键词： Intermolar width interpremolar width maxillary arch maxillary central incisor morphometric

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Compensation trends of the angulation of first molars:retrospective study of 1403 malocclusion cases

引用

International Journal of Oral science 2014年第3期6卷 175-181页

作者： Hong su Bing Han sa Li Bin Na Wen Ma Tian-Min Xu Department of Orthodontics School and Hospital of Stomatology Peking University Department of stomatology Shenzhen People’s Hospital Graduate from school and Hospital of stomatology Peking University Arrail International dental clinic

We investigated the compensatory trends of mesiodistal angulation of first molars in malocclusion cases. We compared differences in the angulation of first molars in different developmental stages, malocclusion classifications and skeletal patterns. The medical records and lateral cephalogrammes of 1 403 malocclusion cases taken before treatment were measured to evaluate compensation of molar angulation in relation to the skeletal jaw. The cases were stratified by age, Angle classification and skeletal patterns. Differences in the mesiodistal angulation of the first molars were compared among the stratifications. We observed three main phenomena. First,angulation of the upper first molar varied significantly with age and tipped most distally in cases aged,12 years and least distally in cases aged.16 years. The lower first molar did not show such differences. second, in Angle Class II or skeletal Class II cases, the upper first molar was the most distally tipped, the lower first molar was the most mesially tipped, and opposite angulation compensation was observed in Class III cases. Third, in high-angle cases, the upper and lower first molars were the most distally tipped, and opposite angulation compensation was observed in low-angle cases. These data suggest that the angulation of the molars compensated for various growth patterns and malocclusion types. Hence, awareness of molar angulation compensation would help to adjust occlusal relationships, control anchorage and increase the chances of long-term stability.

关键词： Angle classification angulation compensation first molar growth stages malocclusion sagittal skeletal patterns verticalskeletal patterns

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Antioxidants: Friend or foe?

引用

Asian Pacific Journal of Tropical Medicine 2017年第12期10卷 1111-1116页

作者： R.sarangarajan s.Meera R.Rukkumani P.sankar G.Anuradha Department of Oral Pathology Madha Dental CollegeKundrathurChennaiIndia Private dental Practitioner Sree Sai Dental CareChennaiIndia Department of Biochemistry and Molecular Biology School of Life SciencesPondicherry UniversityPuducherryIndia Private dental Practitioner Sai Raghav Dental ClinicChennaiIndia

Reactive oxygen species are the intermediates that are formed during the normal metabolic process which are effectively neutralized by the antioxidant system of the *** imbalance in this neutralization process causes oxidative stress which has been implicated as one of the cause in diseases such as Alzheimer's disease, cardiovascular disorders, cancer etc. Research has enabled the use of antioxidants as therapeutic agents in the treatment of various diseases. Literature also puts forth the negative effects of using antioxidants in the treatment of diseases. This review is a compilation of both the beneficial and detrimental effects of use of antioxidants in the treatment of diseases such as cancer, cardiovascular diseases, diabetes and oral diseases.

关键词： Antioxidants Oxidative stress Reactive oxygen species Therapeutic agent

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Effect of colouring green stage zirconia on the adhesion of veneering ceramics with different thermal expansion coefficients

引用

International Journal of Oral science 2013年第4期5卷 236-241页

作者： Guliz Aktas Erdal sahin Pekka Vallittu Mutlu zcan Lippo Lassila Department of Prosthodontics Faculty of DentistryHacettepe University Department of Biomaterials science and Turku clinical Biomaterials Centre University of Turku dental Materials Unit Center for Dental and Oral MedicineClinic for Fixed and Removable Prosthodontics and Dental Materials ScienceUniversity of Zrich

This study evaluated the adhesion of zirconia core ceramics with their corresponding veneering ceramics, having different thermal expansion coefficients （TECs）, when zirconia ceramics were coloured at green stage. Zirconia blocks （N=240; 6 mm x 7 mm x 7 mm） were manufactured from two materials namely, ICE Zirconia （Group 1） and Prettau Zirconia （Group 2）. In their green stage, they were randomly divided into two groups. Half of the specimens were coloured with colouring liquid （shade A2）, Three different veneering ceramics with different TEC （ICE Ceramic, GC Initial Zr and IPs *** Ceram） were fired on both coloured and non-coloured zirconia cores. specimens of high noble alloys （Esteticor Plus） veneered with ceramic （VM 13）（n= 16） acted as the control group. Core-veneer interface of the specimens were subjected to shear force in the Universal Testing Machine （0.5 mm-min-1）. Neither the zirconia core material （P=0.318） nor colouring （P=0.188） significantly affected the results （three-way analysis of variance, Tukey＇s test）. But the results were significantly affected by the veneering ceramic （P=0.000）. Control group exhibited significantly higher mean bond strength values （45.7__.8） MPa than all other tested groups （（27.1__.4.1）-（39.7__.4.7） and （27.4__.5.6）-（35.9___4.7） MPa with and without colouring, respectively）（P^0.001）. While in zirconia-veneer test groups, predominantly mixed type of failures were observed with the veneering ceramic covering ~ 1/3 of the substrate surface, in the metal-ceramic group, veneering ceramic was left adhered 1/3 of the metal surface. Colouring zirconia did not impair adhesion of veneering ceramic, but veneering ceramic had a significant influence on the core-veneer adhesion. Metal-ceramic adhesion was more reliable than all zirconia-veneer ceramics tested.

关键词： adhesion bond strength colouring~ thermal expansion coefficient zirconia

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Isolation and characterisation of human gingival margin-derived sTRO-1/MACs^+ and MACs^-cell populations

引用

International Journal of Oral science 2015年第2期7卷 80-88页

作者： Karim M Fawzy El-sayed sebastian Paris Christian Graetz Neemat Kassem Mohamed Mekhemar Hendr.ck Ungefroren Fred Fndr.ch Christof Drfer clinic for Conservative Dentistry and Periodontology School of Dental MedicineChristian Albrechts University Oral Medicine and Periodontology Department Faculty of Oral and Dental MedicineCairo University Department of Operative and Preventive Dentistry Charite-Universitatsmedizin Berlin Department of clinical Pathology Faculty of MedicineCairo University clinic for Applied Cellular Therapy Christian Albrechts University

Recently,gingival margin-derived stem/progenitor cells isolated via sTRO-1/magnetic activated cell sorting（MACs） showed remarkable periodontal regenerative potential in *** a second-stage investigation,the present study＇s aim was to perform in vitro characterisation and comparison of the stem/progenitor cell characteristics of sorted sTRO-1-positive（MACs~＋） and sTRO-1-negative（MACs^-） cell populations from the human free gingival *** were isolated from the free gingiva using a minimally invasive technique and were magnetically sorted using anti-sTRO-1 ***,the MACs~＋ and MACs^- cell fractions were characterized by flow cytometry for expression of CD14,CD34,CD45,CD73,CD90,CD105,CD146/MUC18 and ***-forming unit（CFU） and multilineage differentiation potential were assayed for both cell *** marker expression was examined using real-time polymerase chain reaction（PCR）.MACs~＋ and MACs- cell fractions showed plastic ***~＋ cells,in contrast to MACs- cells,showed all of the predefined mesenchymal stem/progenitor cell characteristics and a significantly higher number of CFUs（P〈0.01）.More than 95%of MACs~＋ cells expressed CD105,CD90 and CD73;lacked the haematopoietic markers CD45,CD34 and CD14,and expressed sTRO-1 and CD146/***- cells showed a different surface marker expression profile,with almost no expression of CD14 or sTRO-1,and more than 95%of these cells expressed CD73,CD90 and CD146/MUC18,as well as the haematopoietic markers CD34 and CD45 and ***~＋ cells could be differentiated along osteoblastic,adipocytic and chondr.blastic *** contrast,MACs- cells demonstrated slight osteogenic *** MACs~＋ cells showed significantly higher expression of collagen I（P〈0.05） and collagen III（P〈0.01）,whereas MACs^- cells demonstrated higher expression of osteonectin（P〈0.05;MannWhitney）.The present study is the first to compare gingival MACs~＋ and MACs- cell populations demo

关键词： gingival progenitor populations margin periodontal cytometry collagen isolation dental sorting

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Association between innate immunity gene polymorphisms and neonatal sepsis development:a systematic review and meta-analysis

引用

World Journal of Pediatrics 2022年第10期18卷 654-670页

作者： Tamara sljivancanin Jakovljevic Jelena Martic Jelena Jacimovic Nadja Nikolic Jelena Milasin Tanja Lazić Mitrović Department of Neonatology The Obstetrics and Gynecology Clinic“Narodni Front”BelgradeSerbia school of Medicine University of BelgradeBelgradeSerbia Department of Neonatology Mother and Child Health Care Institute of Serbia“Dr Vukan Cupic”BelgradeSerbia Central Library School of Dental MedicineUniversity of BelgradeBelgradeSerbia Department of Human Genetics School of Dental MedicineUniversity of BelgradeBelgradeSerbia

Background The aim of this meta-analysis was to analyze all available data from studies investigating associations between polymorphisms in genes responsible for innate immunity and neonatal sepsis *** A comprehensive literature search,reported following the Preferred Reporting Items for systematic Reviews and Meta-Analyses-s guidelines,was performed with no language *** derived using the PICO(population,intervention,comparison and outcomes)strategy,with data on the genotype distribution for innate immunity gene polymorphisms in newborns with and without *** were analyzed using Review *** Cochran–Mantel–Haenszel test was used to calculate odds ratios with 95%confidence *** was tested using the I2 *** From a total of 9428 possibly relevant articles,33 qualified for inclusion in this systematic *** to the sTrengthening the REporting of Genetic Association studies,23 studies were found to be of moderate quality,while 10 were of low *** results showed an association of the mannose-binding lectin(MBL)exon 1 genetic polymorphism with the risk of culture-proven ***-like receptor(TLR)4 rs4986791 genotype distribution suggests its association with the increased risk of culture-proven *** certainty of evidence per GRADE(Grading of Recommendations,Assessment,Development,and Evaluation)varied from very low to *** bias was not *** Out of the 11 investigated single-nucleotide polymorphisms,this meta-analysis found a possible association between the risk for culture-proven sepsis and MBL exon 1 and TLR4 rs4986791 *** is an evident need for larger well-designed,multicentric observational studies investigating inflammatory gene polymorphisms in neonatal sepsis.

关键词： Genetic Immunity Innate Neonatal sepsis Polymorphism

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Papillae alterations around single-implant restorations in the anterior maxillae:thick versus thin mucosa

引用

International Journal of Oral science 2012年第2期4卷 94-100页

作者： Mi-si si Long—Fei Zhuang Xin Huang Ying-Xin GU Chung-Hao Chou Hong-Chang Lai ~Department of Oral and Maxillofacial Implantology Shanghai Ninth People's Hospital Affiliated Shanghai Jiao Tong University School of Medicine Shanghai China Faculty of Dentistry the University of Hong kong Chian Jing'an dental clinic ShanghaiChina

To evaluate the papilla alterations around single-implant restorations in the anterior maxillae after crown attachment and to study the influence of soft tissue thickness on the papilla fill alteration. According to the inclusion criteria, 32 patients subjected to implant-supported single-tooth restorations in anterior maxillae were included. The patients were assigned to two groups according to the mucosal thickness：（i） group 1, 1.5 mm≤mucosal thickness≤3 mm; and （ii） group 2, 3 mm〈mucosal thickness≤4.5 mm. Assessments of interproximal papillae at the time of crown placement （baseline） and at 6-month postloading （follow-up） were made by two prosthodontists using papilla fill index （PFI）. The mean mucosal thickness was （2.49±0.31） mm （group 1） and （3.81±0.31） mm （group 2） for the two groups respectively. A significant difference in PFI between the groups was detected at the baseline （P〈O.O01）. PFI improvements over time occurred after 6-month follow-up irrespective of the groups. When compared to group 1, the likelihood to obtain papilla fill was significantly higher for group 2 with an odds ratio of 6.05 （P〈O.O01）. The interproximal papilla level around single-implant restorations could improve significantly over time after 6-month restoration according to PFI assessment. The thicker mucosa before implant placement implied a more favorable esthetic outcome in papilla alteration.

关键词： esthetic outcome papilla fill index single-implant restoration soft tissue thickness

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Three-dimensional FEM analysis of stress distribution in dynamic maxillary canine movement

引用

Chinese science Bulletin 2013年第20期58卷 2454-2459页

作者： JING Yan HAN XiangLong CHENG BiHuan BAI Ding state Key Laboratory of Oral Diseases Department of Orthodontics West China Hospital of Stomatology Sichuan University MENG EN dental clinic

An alteration in stress/strain distribution within periodontal ligament (PDL) occurs when the tooth is mechanical stimulated in orthodontic treatment. The majority of previous finite element studies were confined to a static evaluation on initial loading status, and a dynamic long-term analysis was rarely performed in orthodontics. The present study sought to analyze the stress distribution patterns within tooth root, PDL, and alveolar bone during dynamic canine tipping and bodily movement with three-dimensional finite element method in four consecutive therapeutic weeks. We observed that the highest stress was on root surface, secondly alveolar bone, and finally, PDL for either tipping or bodily movement. Throughout the PDL and root surface, the highest stress was always around the cervical area in both patterns of movement through four phases. Moreover, a lower and more uniform stress distribution was produced during bodily movement compared with tipping movement. These results indicated that canine translation might be healthier for periodontal tissue than tipping movement; the cervical region bore a greater load and might also be a susceptible area for tissue damage (except for the apex) regardless of movement pattern.

关键词：三维有限元分析应力分布运动方式三维有限元法口腔正畸最高压力组织损伤 PDL

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

H2 stimulated Raman scattering in a Multi-pass Cell with a Herriott Configuration

引用

Chinese Physics Letters 2015年第11期32卷 67-71页

作者：蔡向龙周灿华周冬建刘金波郭敬为贵林 Key Laboratory of Chemical Lasers Dalian Institute of Chemical Physics Chinese Academy of Sciences Dalian 116023 school of dental clinic Dalian Medical University Dalian 116044

stimulated raman scattering （sRs） is an effective method for expanding the spectral range of high power lasers, especially in the regime of near IR and middle IR. We report the sRs of high pressure H2 with a multiple-pass cell configuration. The sRs with the multiple-pass cell configuration is found to be very efficient for reduction of threshold of the first stokes （s1）. Due to the coherent sRs （CsRs） process, the multiple-pass cell configuration is more effective for reduction of the threshold for the second stokes （s2） sRs and for increasing the conversion efficiency of s2. This contributes to the relatively low conversion efficiency of s1 for the multiple-pass cell configuration. Multiple-pass cell sRs is also found to be very effective for improving the beam quality and the stability of s1.

关键词： sI H2 stimulated Raman scattering in a Multi-pass Cell with a Herriott Configuration sRs

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：