影响口腔高分子粘接剂内聚强度因素的探讨

本文采用柠檬酸—FeCl_3混合溶液、EDTA溶液分别作为牙面处理剂,联用一种牙本质粘接剂和四种牙釉质粘接剂,将复合树脂粘接到牙本质上,通过粘接强度的测试,考察影响高分子粘接剂内聚强度的因素。研究结果制明: 1.对于牙本质粘接剂与不含填料的牙釉质粘接剂联用体系,用柠檬酸—FeCl_3混合液处理牙面后的粘接强度比用EDTA处理的低。这可能是用前者处理时铁离子以Fe~3+存在于牙面,它对粘接剂中的单体有阻聚作用而影响粘接剂的内聚强度。 2.氧气对粘接剂单体有阻聚作用。若粘接剂中含有更容易与氧气反应的还原性物质,则可降低氧气对粘接剂中单体的阻聚作用而提高粘接剂的内聚强度。 3.对于牙本质粘接剂与含填料的牙釉质粘接剂联用体系,用柠檬酸—FeCl_3混合液处理牙面后的粘接强度比用EDTA处理的高。这种差异取决于表面处理时牙面的脱钙程度和牙本质小管的开口大小。前者使牙面脱钙和牙本质小管的开口程度较大,这有利于含填料的粘接剂树脂在牙面的充分浸润和渗透。由于此联用体系含有增强的填料,其内聚强度受Fe~(3+)阻聚作用的影响较小。     

反复呼吸道感染儿童的骨强度分析

目的 :探讨儿童反复呼吸道感染(RRTIs)与骨强度水平的相关性。方法 :随机选取1～3岁的318例RRTIs患儿作为研究组,312例正常体检儿童作为对照组,对比2组的骨强度水平和骨强度不足率;对比研究组中不同性别RRTIs患儿骨强度水平和骨强度不足率;分析研究组的骨强度水平与年龄的相关性。结果 :研究组的骨强度水平低于对照组(P=0.00);研究组的骨强度不足检出率高于对照组(P=0.00);研究组内不同性别骨强度水平差异无统计学意义(P=0.23),研究组内不同性别骨强度不足检出率差异亦无统计学意义(P=0.44);研究组儿童骨强度水平随着年龄的增长而上升,两者之间呈正相关(r=0.269,P=0.000)。结论 :RRTIs患者骨强度水平明显减低,年龄越小,骨强度水平越低。检测RRTIs患者骨强度水平对于RRTIs并发骨强度不足的诊断、治疗以及预后的评估等方面均具有重要意义。     

腰椎间盘刚度和强度的实验研究

本实验采用８具正常成人男性新鲜腰骶段一，测得腰椎间盘的压缩刚度是１３１４Ｎ／ｍｍ；剪切刚度是２４５Ｎ／ｍｍ；扭转刚度是６．５Ｎｍ／ｄｅｇｒｅｅ；扭转强度为８０．３Ｎ，同时对髓核摘除和后部结构切除后腰椎间盘的刚度和扭转强度变化进行测试，结果显示，髓核摘除和后部结构切除后腰椎间盘刚度和扭转强度下降，其结果有统计学意义（Ｐ，０．０５），其中后部构切除后扭转刚度下降５１％，扭转强度下降４４％。     

合金与树脂的粘接强度及影响因素

金属树脂修复体已广泛应用于口腔修复。金属和树脂之间有良好的结合力是保证贴面树脂在口腔内发挥正常功能的先决条件，即金属树脂界面需要有理想的结合，达到一定的强度。粘接强度主要包括剪切结合强度和抗张结合强度。多种因素可能影响二者结合强度，如合金、金属表面处理、金属表面调节剂、底胶、粘接剂，粘接系统和树脂等。本文就相关研究进展作一综述。     

简易视野计的研制

目的：研制一种简易视野仪。方法：利用球面型发光二极管矩阵随机变换发光管的位置及发光强度检测患者的视觉反应。结论：该仪器对补充视功能检查，及时发现某些眼病有一定的诊断价值。     

人的周围神经拉伸强度测定

本文取材于7具男性成年尸体,98条周围神经,进行拉伸强度的测试,得出视神经、动眼神经、上颌神经、迷走神经、尺神经、正中神经及坐骨神经的拉伸强度数值,发现脑神经与脊神经之间,拉伸强度存在明显的差别。迷走神经与脊神经的拉伸强度几乎完全相同。尽管神经是粘弹性材料,但通过测试其拉伸强度,还是表现出一定的集中趋势,符合生物力学特征。     

a-氰基丙烯酸正辛酯反复粘接人胫骨皮质骨的生物力学研究

在医用粘接胶固定骨折断端时,往往需要反复粘接固定才能达到满意的复位效果。本实验将新鲜人胫骨干复温后,于胫骨中段横断,取前方的皮质骨制成规则的三棱形,仔细处理断端骨面及三棱形的侧面,测量其面积后用于抗拉强度、剪切强度和弯曲强度的测定。在37℃生理盐水中用细砂纸打磨粘接面去除残余于骨面的胶体后,拭干各粘接面,再次测定抗拉、剪切、弯曲等指标,观察其变化。结果显示,第一次粘接的剪切强度大于第二次的剪切强度,二者之间有显著差异(P<0．05);第二次粘接的剪切强度大于第三次粘接的剪切强度,但无统计学显著差异(P>0．05);抗拉强度随粘接次数增加而减小,但各组之间无显著差异(P>0．05);在胶体断裂前,其弹性模量和刚度系数无显著差异(P>0．05)。在本实验中,初次粘接的抗拉强度为5．93 MPa,剪切强度为9．11 MPa,剪切实验中,被粘接的骨面的微形态结构的变化对剪切强度影响较大。在剪切强度的测定中,每次测定应去除1～2 mm的粘接面的骨质,以保证实验结果的可靠性。而拉伸试验和弯曲试验中,由于粘接面微形态结构的变化对实验结果无显著影响,去除骨面残留的胶体后即可进行反复实验。在临床操作中,对于剪切应力较大的部位,应一次粘接固定,以免反复粘接后影响粘接的固定效果。     

简式情感强度量表中文版的信效度检验

目的:建立简式情感强度量表(Short Affect Intensity Scale,SAIS)的中文版,并检验其信、效度。方法:831名大学生完成了SAIS等量表,有63人完成120张情绪图片的愉悦度和唤醒度的评分,另有91人间隔1个月第二次完成了SAIS。结果:SAIS中文版的Cronbach’sα系数总量表为0.86,三因子分别为0.86、0.75和0.84;条目间平均相关系数总量表为0.30,三因子分别为0.43、0.32和0.46;间隔1个月的重测信度总量表为0.83,三因子分别为0.79,0.82,0.85;各因子间的相关系数在0.39～0.62之间;正性情感强度与正性图片愉悦度及唤醒度的得分均存显著正相关,负性情感强度与负性图片的愉悦度显著负相关,而与负性图片的唤醒度得分显著正相关。验证性因素分析的指标:GFI为0.93,ACFI为0.92,CFI为0.95;RMSEA为0.045;条目对因子负荷系数在0.39-0.84之间。结论:简式情感强度量表中文版具有良好的信、效度,适用于我国大学生的情感强度评估。     

合金与树脂的粘接强度及影响因素

金属树脂修复体已广泛应用于口腔修复。金属和树脂之间有良好的结合力是保证贴面树脂在口腔内发挥正常功能的先决条件,即金属树脂界面需要有理想的结合,达到一定的强度。粘接强度主要包括剪切结合强度和抗张结合强度。多种因素可能影响二者结合强度,如合金、金属表面处理、金属表面调节剂、底胶、粘接剂,粘接系统和树脂等。本文就相关研究进展作一综述。     

疝补片的微观结构和力学性能研究

目的分析不同品牌疝补片的微观结构及拉伸、顶破强度进而评估不同疝补片的力学性能。方法分别使用天平、显微镜对常见的15种疝补片进行质量和微观结构测试,并分别使用拉伸试验机与顶破试验机来检测疝补片的拉伸性能与顶破性能,并对疝补片进行力学性能分析。结果疝补片的编织结构为菱形、多边形和圆形。腹股沟补片的平均质量为0.08 mg/mm2,腹壁疝补片的平均质量为0.18 mg/mm2。G3~G6疝补片的丝径较大,G12的网孔率较低。在拉伸性能测试中,G15的拉伸强度最大,重量型补片中G12、G14的拉伸强度较小,轻量型补片中G1、G2、G7的拉伸强度较小。在顶破性能测试中,G3、G9、G15疝补片的顶破强度最大,重量型补片中G12、G13、G14的顶破强度较小,轻量型补片中G1、G2、G4的顶破强度较小。结论多边形网孔且大网孔率的疝补片具有更好的力学性能,为优化疝补片提供了实验依据,有望为相关的研究和应用提供更好的支持。     

In vitro bioactivity and phase stability of plasma-sprayed nanostructured 3Y-TZP coatings

In this work, plasma-sprayed nanostructured zirconia coatings stabilized with 3 mol.% yttria (3Y-TZP) were deposited on Ti substrates. The microstructure and phase composition of coatings were characterized using scanning electron microscopy and X-ray diffraction. The in vitro bioactivity of coatings was evaluated by examining the formation of bone-like apatite on its surface in simulated body fluid. MG63 cell lines were cultured on the coating to investigate its cytocompatibility. The crystalline phase of the as-sprayed coating was tetragonal zirconia, and no monoclinic zirconia was detected. The size of the grains on the as-sprayed coating surface was less than 100 nm. The apatite could precipitate on the surface of the coating immersed in simulated body fluid for 28 days while no apatite was formed on the surface of 3Y-TZP ceramic control, indicating that the bioactivity of the coating is superior to the ceramic with the same composition. It also revealed that the polished coating whose nanostructural outmost layer was removed was bioinert, implying the significance of the nanosized grains for its bioactivity. MG63 cells could adhere, grow and proliferate well on the coating surface, indicating that the coating had good cytocompatibility. Phase stability of plasma-sprayed 3Y-TZP coating was evaluated under hydrothermal conditions at 134 °C. It revealed that the plasma-sprayed nanostructured zirconia coating was more sensitive to aging than that of zirconia ceramics.     

Microstructure,bioactivity and osteoblast behavior of monoclinic zirconia coating with nanostructured surface

A monoclinic zirconia coating with a nanostructural surface was prepared on the Ti–6Al–4V substrate by an atmospheric plasma-spraying technique, and its microstructure and composition, as well as mechanical and biological properties, were investigated to explore potential application as a bioactive coating on bone implants. X-ray diffraction, transmission electron microscopy, scanning electron microscopy and Raman spectroscopy revealed that the zirconia coating was composed of monoclinic zirconia which was stable at low temperature, and its surface consists of nano-size grains 30–50 nm in size. The bond strength between the coating and the Ti–6Al–4V substrate was 48.4 ± 6.1 MPa, which is higher than that of plasma-sprayed HA coatings. Hydrothermal experiments indicated that the coating was stable in a water environment and the phase composition and Vickers hardness were independent of the hydrothermal treatment time. Bone-like apatite is observed to precipitate on the surface of the coating after soaking in simulated body fluid for 6 days, indicating excellent bioactivity in vitro. The nanostructured surface composed of monoclinic zirconia is believed to be crucial to its bioactivity. Morphological observation and the cell proliferation test demonstrated that osteoblast-like MG63 cells could attach to, adhere to and proliferate well on the surface of the monoclinic zirconia coating, suggesting possible applications in hard tissue replacements.     

饰瓷温度烧结对氧化锆陶瓷与树脂黏结剂剪切强度的影响

背景：研究已证实硅烷偶联剂和喷砂等表面处理方式,以及增加氧化锆陶瓷表面的微裂纹可提高氧化锆陶瓷与树脂黏结剂间的黏结强度,但有关多次反复烧结是否会对氧化锆陶瓷黏结剪切强度产生影响尚缺少相关研究。 目的：测试饰瓷温度烧结对牙科氧化锆陶瓷与树脂黏结剂黏结剪切强度的影响。 方法：从40片氧化锆瓷片随机选择20片,分成 5组,按照常规烧结程序分别烧结0(对照组),2,4,6,8次,热处理起始温度为500 ℃,最终温度1 000 ℃,升温速率55 ℃/min,抽真空时间7 min。每次烧结最终温度恒定不变。将各组分别用树脂黏结剂与剩余未烧结的陶瓷片对位黏结,用万能材料试验机测黏结界面的剪切强度;使用扫描电镜观察剪切后的试件断面形貌。 结果与结论：烧结4,6,8次组试件剪切强度高于对照组(P < 0.05);烧结2次组试件剪切强度稍高于对照组,但差异无显著性意义(P > 0.05);烧结8次组试件剪切强度高于烧结4,6次组(P < 0.05)。未烧结氧化锆陶瓷表面未见裂纹;经过2次烧结后表面可见细微裂纹;经过4次烧结后表面可见裂纹增多;经过6次烧结后表面已经开始有明显变化,裂纹增多并伴有细微空隙产生,少量黏结剂残留;经过8次烧结后表面可见裂纹与空隙明显增多并有黏结剂残留。表明经过4,6,8次烧结后的氧化锆陶瓷对树脂黏结剂有较好的黏结剪切强度,烧结8次后的黏结剪切强度最强。中国组织工程研究杂志出版内容重点：生物材料;骨生物材料; 口腔生物材料; 纳米材料; 缓释材料; 材料相容性;组织工程全文链接：     

口腔氧化锆陶瓷的粘接方法

背景：氧化锆陶瓷因具有良好的理化性能和生物相容性在口腔修复重建领域被广泛应用,但如何对氧化锆陶瓷表面进行改性,以提高修复体与牙体组织的粘接强度成为目前临床工作中的难点。 目的：综述口腔氧化锆陶瓷的粘接方法。 方法：应用计算机检索PubMed 数据库,检索关键词为“zirconia, silane coupling agent, resin cement, bonding”。 结果与结论：通过化学摩擦硅涂层系统结合新型混合非功能性硅烷偶联剂对氧化锆瓷进行表面处理,利用小粒径(50 µm)的含硅颗粒氧化铝粉末对氧化锆进行喷砂,形成含硅粒子的粗糙覆盖表层,此系统可降低传统喷砂对瓷边缘薄弱部位的损伤,提高修复体边缘密合度;新型混合非功能性硅烷偶联剂与陶瓷表面可形成稳定且高强度的硅氧烷键,其水解稳定性远高于传统的硅烷偶联剂,利用硅氧烷在界面处与聚合物交联形成的互穿网络体系,可更有效地将树脂共价接枝到硅烷表面,有效提高氧化锆陶瓷与树脂的粘接强度,为修复体提供足够的固位力,提高临床修复成功率。中国组织工程研究杂志出版内容重点：生物材料;骨生物材料; 口腔生物材料; 纳米材料; 缓释材料; 材料相容性;组织工程全文链接：     

Low-temperature degradation in zirconia with a porous surface

Today there is growing interest in zirconia in the dental field, but its use is still recent. Dental zirconia is mainly found in the form of yttria-stabilized zirconia crowns, bridges and abutments, and several companies are developing zirconia implants as an alternative to the standard biomedical grade titanium. In order to favor bone in-growth and osseointegration of zirconia implants, several strategies are now being explored to process rough and/or porous surfaces. The aim of this paper was to evaluate the resistance to environmental degradation of yttria-stabilized zirconia coated with a porous layer. We show that specific conditions of processing to generate the porous layer at the surface can lead to an accelerated tetragonal-monoclinic transformation of the porous layer in the presence of water. The impact of the transformation was evaluated in terms of structural integrity. Bending strength was not affected but the cohesion of the porous coating and its adhesion with the dense part deteriorated. We show that other processing conditions insure much better stability. Low-temperature degradation resistance of such porous surfaces should therefore be carefully followed and controlled in order to avoid critical problems in the future.     

Towards long lasting zirconia-based composites for dental implants. Part I: Innovative synthesis,microstructural characterization and in vitro stability

In order to fulfill the clinical requirements for strong, tough and stable ceramics used in dental applications, we designed and developed innovative zirconia-based composites, in which equiaxial α-Al₂O₃ and elongated SrAl₁₂O₁₉ phases are dispersed in a ceria-stabilized zirconia matrix. The composite powders were prepared by an innovative surface coating route, in which commercial zirconia powders were coated by inorganic precursors of the second phases, which crystallize on the zirconia particles surface under proper thermal treatment. Samples containing four different ceria contents (in the range 10.0–11.5 mol%) were prepared by carefully tailoring the amount of the cerium precursor during the elaboration process. Slip cast green bodies were sintered at 1450 °C for 1 h, leading to fully dense materials. Characterization of composites by SEM and TEM analyses showed highly homogeneous microstructures with an even distribution of both equiaxial and elongated-shape grains inside a very fine zirconia matrix.Ce content plays a major role on aging kinetics, and should be carefully controlled: sample with 10 mol% of ceria were transformable, whereas above 10.5 mol% there is negligible or no transformation during autoclave treatment.Thus, in this paper we show the potential of the innovative surface coating route, which allows a perfect tailoring of the microstructural, morphological and compositional features of the composites; moreover, its processing costs and environmental impacts are limited, which is beneficial for further scale-up and real use in the biomedical field.     

Coatings on zirconia for medical applications

In order to combine the mechanical properties of a high-strength inert ceramic (yttria-stabilised zirconia, ZrO2-3%Y2O3, defined as zirconia in the text) with the specific properties of bioactive materials, some zirconia samples were coated by two bioactive phosphosilicate glasses and glass-ceramics: RKKP and AP40. Coatings of about 200-300 microm thickness were prepared by a simple and low-cost firing method. They were characterised by optical and scanning electron microscopy (SEM) and compositional analysis (EDS). The adhesion of the coatings on zirconia was tested by shear tests. Vickers indentations at the coating/zirconia interface were performed in order to observe the crack propagation path. The reactivity of glasses and glass-ceramics coatings towards a simulated body fluid (SBF), having the same ion concentration as that of human plasma, was evaluated and compared to that of the bulk glass and glass-ceramics, by examining the morphology of the reaction layer formed on the surface of the coated zirconia after one month of soaking in the SBF at 37 degrees C.     

上釉技术对氧化钇稳定四方相氧化锆多晶陶瓷粘接及力学性能的影响

文题释义：氧化钇稳定四方相氧化锆多晶陶瓷：是以氧化钇为稳定剂、四方相为主要物相的氧化锆陶瓷，其具有较高的抗弯强度(900-1 200 MPa)和断裂韧性(9-10 MPa·m^1/2)。由于这些优异的机械性能，氧化钇稳定四方相氧化锆多晶陶瓷成为口腔冠桥修复中应用最广泛的陶瓷之一。 相变增韧机制：为氧化锆增韧的一种方法。稳定剂使四方相氧化锆在室温下可以处于亚稳态，但是在应力作用下亚稳态的四方相氧化锆易转化为单斜相氧化锆，同时伴有3%-5%的体积膨胀，这个过程能弥合微裂纹且消耗断裂能，提高氧化锆陶瓷的韧性。 背景：任何表面处理都应在不损害原有氧化钇稳定四方相氧化锆多晶陶瓷强度的前提下提高其粘接强度。目前缺乏上釉技术对氧化钇稳定四方相氧化锆多晶陶瓷粘接强度影响的资料，并且其对氧化钇稳定四方相氧化锆多晶陶瓷力学性能的影响尚不明确。 目的：评估上釉技术对氧化钇稳定四方相氧化锆多晶陶瓷力学行为及其与树脂水门汀粘接强度的影响。 方法：制作氧化钇稳定四方相氧化锆多晶陶瓷试件并随机分为4组：A组，表面不做任何处理；B组，110 μm氧化铝颗粒喷砂；C组，上釉+氢氟酸酸蚀；D组，上釉+氢氟酸酸蚀+硅烷化。检测每组试件的表面显微形貌、粗糙度、晶相结构、元素组成、剪切粘接强度和弯曲强度，并观察剪切粘接强度测试后所有断面的断裂模式。 结果与结论：①经表面处理后的试件粗糙度明显增大，降序排列依次为C组(0.62±0.01) μm、D组(0.55±0.02) μm、B组(0.11±0.02) μm、A组(0.05±0.01) μm，5组间粗糙度比较差异有显著性意义(P < 0.05)；②B组试件表面含有2.2%单斜相氧化锆，而其他组含量均为零；③除锆和氧2种元素外，B组还含有铝元素6.49%，C和D组分别含有硅元素18.67%和25.78%；④A、B、C、D组的剪切粘接强度分别为(3.11±0.40)，(4.23±0.45)，(6.62±0.60)，(10.46±0.83) MPa，组间两两比较差异均有显著性意义(P < 0.05)；⑤A、B、C和D组的三点弯曲强度分别为(961.07±75.53)，(1 234.73±114.09)，(1 024.28±120.51)，(1 036.09±80.10) MPa，其中A、C和D组两两比较差异无显著性意义(P > 0.05)，B组与A、C、D组比较差异有显著性意义(P < 0.05)；⑥结果表明，上釉技术未明显提升氧化钇稳定四方相氧化锆多晶陶瓷的弯曲强度，但上釉后经氢氟酸蚀刻并硅烷化处理可显著增强氧化钇稳定四方相氧化锆多晶陶瓷与树脂水门汀之间的粘接强度。 ORCID: 0000-0002-8066-2498(徐小敏) 中国组织工程研究杂志出版内容重点：生物材料；骨生物材料; 口腔生物材料; 纳米材料; 缓释材料; 材料相容性；组织工程     

Hard-tissue-engineered zirconia porous scaffolds with hydroxyapatite sol-gel and slurry coatings

A zirconia (ZrO(2)) porous scaffold was coated with a gradient apatite layer to induce osteoconductivity with the use of a combination of sol-gel and powder slurry methods. The ZrO(2) was used to impart mechanical strength and the apatite layer was coated for functional biocompatibility. The coating layer, from the outside in, was composed of sol-gel hydroxyapatite (HA)/slurry HA/slurry FA. The sol-gel coating powder had a lower crystallinity than the slurry coating powder. The sol-gel HA coating over the HA/FA slurry coating layer made the surface very smooth. The sol-gel coating over the slurry coating layer enhanced the bonding strength up to 33 MPa. The dissolution rate of the sol-gel/slurry coating layer was much higher than that of the slurry coating. Moreover, the rate could be controlled by altering the heat-treatment temperature of the sol-gel HA layer. The MG63 cells cultured on these materials grew and spread in a different manner, depending on the coating layer. However, the proliferation rates of the cells on both coating systems were not much different.     

氧化锆与纳米羟基磷灰石陶瓷的剪切实验

BACKGROUND: Nano-hydroxyapatite as a surface modification material that is bonded to the surface of the zirconia ceramics upon sintering at high temperature can improve bone-inducing activity and bone bonding strength of the zirconia ceramics. Moreover, the sintering temperature is crucial for performance and bonding of the composite. OBJECTIVE: To detect the shear strength of nano-hydroxyapatite ceramics coating bonded to zirconia ceramics at different sintering temperatures. METHODS: Nano-hydroxyapatite slurry was prepared using sol/gel technology. Thereafter, 20 zirconium green bodies were coated with nano-hydroxyapatite slurry and randomly divided into four groups. Then, the specimens were put into non-pressure sintering furnace and sintered at 1 300, 1 400, 1 500, and 1 550 ℃, respectively. At last, we measured the shear strength of all the specimens after sintering by universal testing machine, and analyze the type of fractures. RESULTS AND CONCLUSION: With the rising of sintering temperature, the shear strength of the specimens was gradually increased, and there were significant differences between the four groups [(4.04±1.19), (6.60±0.95), (16.51±1.93), (80.47±19.31) MPa, P < 0.05]. Within the scope of 1 550 ℃, the sintering temperature was positively relative to the shear strength of specimens. These findings indicate that in the certain temperature range, the higher the sintering temperature, the greater the shear strength of the bonding interface between zirconia and nano-hydroxyapatite. When the sintering temperature is 1 550℃, the shear strength of the bonding interface is the highest.