氧化锆陶瓷用于牙科修复体的研究进展

综述了氧化锆陶瓷在牙科修复体方面的研究和应用,特别是作为复合树脂填料,金属烤瓷饰瓷的功能性组分,微晶玻璃烤瓷的成核剂和补强相,全氧化锆牙科修复体方面的进展.氧化锆陶瓷的高烧结温度和高加工成本制约了其发展和进步,降低烧结温度和减少加工成本是近期关注的焦点.采用添加液相烧结助剂可大幅降低烧结温度,同时降低氧化锆强度,达到与天然牙相似,从而可以采用CAD/CAM机加工.     

口腔预备体颈缘线快速提取技术研究

由于高质量的全瓷冠、桥体制作的需要，在过去的16年里，基于CAD/CAM的口腔修复体制作技术成为研究的热点。预备体颈缘线的自动提取技术是口腔CAD/CAM修复工艺边缘密合的关键环节，修复冠的边缘密合性将对患者的牙龈健康有重要影响。本文提出了半自动颈缘线提取算法，首先，采用二次曲面拟合估算网格点的曲率；接着，利用“方向”追踪方法快速提取初始特征线；然后，利用“曲率”吸引策略保持能量最小的方法优化网格表面的特征线。最后的应用实例证实本文算法是有效的、可行的，满足临床应用要求。     

对比两种一体化基台冠对种植体周边缘骨水平的影响

目的 评价钛金属底座个性化氧化锆一体化基台冠对种植体边缘骨水平的影响.方法 40例符合后牙区单颗种植二期修复患者随机分为:对照组(A组)采用传统成品基台+氧化锆全冠一体化基台冠修复,实验组(B组)采用钛金属底座个性化氧化锆一体化基台冠修复.分别测量并记录修复后不同时期两组患者种植体周边缘骨水平变化量.结果 两种一体化基...     

烤瓷贴面与全瓷冠在牙齿修复中应用的效果对比

对比研究烤瓷贴面与全瓷冠在牙齿修复中应用的效果。选取高台县人民医院收治的牙齿修复患者86例(185颗),根据患者牙齿情况选择修复材料,接受烤瓷贴面修复的患者46例(97颗),接受全瓷冠修复的患者40例(88颗),对比两种修复方式患者满意度及远期完整性。两种修复方式患者主观满意度相比无明显差异(P0.05),全瓷冠患者客观满意度95.00%显著高于烤瓷贴面患者80.43%(P0.05);修复治疗两年后,全瓷冠完好率98.86%显著高于烤瓷贴面92.78%(P0.05)。烤瓷贴面与全瓷冠在牙齿修复中均能起到美容作用,全瓷冠修复患者满意度更高,且远期完整性更佳。     

口腔种植技术的应用探讨

目的:探讨ITI Straumann种植牙系统的临床应用效果,并探讨其发展前景.方法:对我院54例牙列缺损患者采用ITI Straumann种植牙系统植入的106颗牙齿为研究对象,3~6个月以后对其行上部结构修复术,并在术后观察牙体的结合情况、修复体情况、患者的满意率.结果:对55例患者106颗种植牙体进行随访6~24个月,所有患者牙体全部成功植入,成功率为100%.患者的满意率为92.75%.结论:采用口腔种植义齿修复牙列缺损有效率高,非常适合在规模不大的口腔科应用.     

部分烧结氧化锆陶瓷的齿科修复体磨削加工

介绍了口腔修复用部分烧结氧化钇稳定四方相氧化锆(Y-TZP)陶瓷的材料性能及切削性能,分析了齿科CAD/CAM修复的技术流程和磨削加工齿科修复体所需具备的一些基础理论与技术装备,给出了一个基于部分烧结氧化锆材料的磨牙冠磨削加工实例,其具体加工分2步:1)采用Ф1.6 mm的柱形标准金刚石磨针,以较大材料去除率的磨削参数(主轴转速40 000 r/min,磨削深度0.2 mm,进给速度300 mm/min)快速加工出磨牙冠的型面,以提高齿科修复的效率。2)因磨牙冠表面形状复杂,故采用Ф0.8 mm的球头锥形磨针,精磨参数采用:主轴转速40 000r/min,磨削深度0.06 mm,进给速度100 mm/min,加工出光洁的磨牙冠表面,形貌检测表明其表面质量高,符合医学齿科修复的要求。     

金属烤瓷修复体远期效果评价

目的：评价金属烤瓷修复体修复的远期效果.方法：选择280例患者制作310颗金属烤瓷修复体,参照美国公共健康协会（USPHS）的修正标准进行临床评价.结果：经3-5a的临床观察,无颜色变化;修复5a后修复体颈缘密合度为91.9%;牙龈炎为17.1%;崩瓷为9.2%;基牙继发病变为13.2%;颈缘变色为26.3%.结论：以求最终提高修复的成功率和远期效果,应严格掌握适应证,规范牙体制备,技工制作,临床试合,定期检查,正确的刷牙方法.     

计算机辅助设计与计算机辅助制作在口腔临床的应用观察

CAD/CAM全瓷修复体因为具有很好的生物相容性和非常好的边缘密闭性,不仅仅是应用于瓷嵌体和单冠的制作,也可以多单位的固定桥修复,其在口腔修复领域的应用越来越广泛。     

石膏上水基电泳沉积纳米氧化锆的结构和性能特点

研究评估了水基电泳沉积作为口腔纳米氧化锆全瓷修复体成型方式的可能性.试验通过配置固含量为85wt%的低粘度水基悬浮液,在齿科专用石膏上直接以电泳沉积的方式成型出纳米氧化锆陶瓷预成体,并研究了其结构和性能特点.结果显示：水基电泳沉积成型的方式可以成型出结构非常均一的纳米氧化锆预成体,其表面光滑,外形与石膏基底外形一致,在微观结构上与已商品化的齿科CerconCAD/CAM氧化锆预成瓷块相比,结构更加致密、均匀,且未见明显气泡、裂缝等缺陷 要达到〉99.9%TD,水基电泳沉积成型的纳米氧化锆3Y-TZP所需的烧结温度为1320℃,低于常规的干压成型工艺,力学性能与Cercon氧化锆全瓷修复材料相近,能够满足临床需要.     

浅谈cercon全瓷冠的CAD/CAM操作系统

介绍了cercon(二氧化锆结构陶瓷)全瓷冠的计算机辅助设计(CAD)与计算机辅助制作(CAM)的发展历程、临床应用及其优越性,并对全瓷冠的未来作出展望.     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that     

On the Thermodynamic Limit for Responses to Static Electromagnetic Fields

For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the     

Call for Papers

<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with     

Journal of Donghua University ( English Edition) Contents of Volume 31

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