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1.
目的:研究酪蛋白激酶-2相互作用蛋白-1(CKIP-1)对小鼠股骨松质骨与皮质骨的骨量、胶原变化的影响,及其在调节股骨、下颌骨生物力学中的作用。方法:取3月龄Ckip-1基因敲除(KO)小鼠作为实验组,野生型(WT)小鼠作为对照组(同窝、雄性)(n=5)。分别对小鼠股骨松质与皮质骨进行影像学Micro CT扫描,组织学丽春红三色染色、 I型胶原免疫组化染色、天狼星红染色,及力学三点弯曲实验,定量分析,评估Ckip-1对松质与皮质骨量、胶原含量与比例、及生物力学强度的影响。结果:Ckip-1 KO小鼠,股骨松质骨:骨量提高,胶原含量增加,但比例不变,生物力学强度增强;股骨皮质骨:骨量、胶原含量、比例无显著影响,复合型下颌骨组织生物力学显著增强。结论:Ckip-1对松质骨各项性能指标影响较大,对皮质骨无显著影响,可负调控骨组织的生物力学强度。  相似文献   

2.
目的:研究植入下颌骨缺损区的生物活性玻璃陶瓷(bioactive glass ceramics,BGC)远期力学性能变化。方法:对两例因肿瘤行部分下颌骨切除生物活性玻璃陶瓷植入术后8-10年的BGC标本以植入前的BGC和人下颌面骨皮质作对照,用三点弯曲法测定样品的抗弯强度以及弹性模量。结果:BGC植入术后8-10年抗弯强度仍然明显低于骨皮质。弹性模量稍增加且高于皮质骨。结论:BGC复合自体骨植入有良好的骨替代效果,克服其脆性后有较大的临床应用前景。  相似文献   

3.
目的:通过扫描电镜、透射电镜观察,了解冷冻自体下颌骨复合髂骨移植的愈合过程及机理。方法:8只健康家兔实施冷冻自体下颌骨复合髂骨移植,在对侧下颌骨行新鲜髂骨移植作对照。术后2周、4周各处死4只动物,制作标本进行扫描电镜、透射电镜观察。结果:实验组:术后2周主要表现为死骨,边缘有散在成骨细胞及点状钙盐沉积,透射电镜可见散在的代谢活跃的成骨细胞、幼稚骨细胞和破骨细胞。4周时植骨成骨活跃,新生骨占据大部分空间,切面上密布大量活跃成骨细胞、幼稚骨细胞及软骨细胞。对照组:2周时主要为死骨,边缘处只有非常少量的钙盐沉积,软骨细胞及成骨细胞活性差。4周时晶体沉积量显著增加但仍明显少于实验组,在皮质表面形成较厚的透明软骨,切面上可见很多中等活性的软骨细胞。结论:冷冻自体下颌骨复合髂骨移植术后早期有活跃的骨质再生,提示该手术方法用于下颌骨缺损整复是可行的。  相似文献   

4.
目的:本文考察牙种植有限元分析中下颌骨模型几种前处理方法下的应力分布情况和特点。方法:采用螺旋CT扫描、mimics软件等建立下颌骨三维有限元模型,在有限元软件中模拟咬合力加载,分析种植体对于下颌骨应力分布情况。结果:三种不同处理情况下的下颌骨应力分布有较大的共同点,应力都主要集中在皮质骨部分,在松质骨部分三种模型应力值显著低于皮质骨部分。结论:可根据不同应用选择下颌骨模型前处理方法,在不影响考察松质骨应力分布的条件下,模型前处理可作适当简化。  相似文献   

5.
目的:观察复合种植体(CI)基底材料Ti-75合金(TA)的生物学特性和TA-涂层结合强度在种植体骨界面结合强度中的表现。方法:应用穿皮质骨种植模型。在双侧犬股骨内种植TA和CI共32枚;在术后3个月和6个月,处死动物取材;种植体骨界面进行组织学观察和推出试验,并对断裂后的种植术骨界面进行扫描电镜观察。结果:TA与CI均与骨组织形成了骨柱结合;CI骨界同的剪切强度高度于TA(P<0.01);CI骨界面断裂在部分在涂层骨组织界面和涂层内部,很少在涂层TA界面。结论:TA与CI均具有良好的生物相容性;TA涂层界面具有足够的结合强度,是值得进一步研究的复合种植体基底材料。  相似文献   

6.
目的:应用有限元法建立生物相似性和力学相似性较高的下颌骨三维模型,分析并比较下颌升支部牵张成骨时不同加载方式对下颌骨内部应力分布及位移趋势的影响。方法:以正常青年男性下颌骨为标本,用CT断层扫描技术与计算机软件相结合,在微机上建模。采用受拉杆单元、受压间隙元等模拟肌肉、韧带的边界约束条件,在下颌升支部模拟骨皮质切开。结果:建立了包括下颌骨、颞下颌关节、肌肉和韧带,局部骨皮质断开的三维有限元模型。结论:提高了模型的相似性,为下颌升支部牵张成骨的进一步研究奠定了基础。  相似文献   

7.
山羊下颌骨牵张成骨的生物力学研究   总被引:4,自引:0,他引:4  
目的:探讨下颌骨牵张成骨进程中骨段间张力强度的变化特征。方法:8只山羊右下颌骨行骨皮质切开术并牵张后,对牵张期的每个工作日内的牵张前骨段间张力值、牵张时张力值和牵张后张力值进行测量分析,同时对固定期内的骨段间张力也进行了测量分析。结果:牵张期内骨段间张力值逐日显著增高,牵张期结束时达到峰值;固定期内张力值逐周显著下降,至骨皮质切开术9周后与施加牵张力前正常状态时骨段间张力值无显著性差异。结论:下颌骨牵张成骨进程中骨段间延长区组织所承受的张力值表现为先上升后下降的走势,这可能与骨周组织的适应性增长和新骨强度的逐渐增高有关。  相似文献   

8.
本文通过测量新鲜人体下颌骨皮质骨的拉伸弹性模量和孔隙率,研究其孔隙率对拉伸弹性模量的影响。实验结果表明:人体下颌骨皮质骨的孔隙率很低,随着孔隙率的增加,其弹性模量非线性降低。  相似文献   

9.
咬肌再附着界面的生物力学研究   总被引:3,自引:1,他引:2  
目的:研究山羊咬肌与下颌骨皮质骨面和松质骨面再附着的生物力学特性变化。方法:9只成年山羊为研究对象,其中1只为正常对照,实验组山羊双侧下颌骨咬肌附着从骨面剥离,附着区骨面平均分为两部分,分别保留原骨面或去除皮质骨,暴露松质骨,咬肌原位缝合,术后2,4,8,12周采集标本,进行生物力学测试。结果:生物力学检测表明,2-12周肌-骨界面附着强度随时间延长有显著增强,而同一时间两种骨面的肌附着强度无显著差异。结论:咬肌再附着的形成与附着骨面结构无关。  相似文献   

10.
目的:研究生物珊瑚、胶原和rhBMP-2复合人工骨修复兔下颌骨缺损的效果。方法:选择36只兔下颌骨缺损模型,分别采用新鲜自体骨,生物珊瑚和生物珊瑚、胶原和rhBMP-2复合人工骨修复,大体、组织切片、X线、统计学等方法进行分析。结果:修复兔下颌骨缺损,合成人工骨形成新骨的时间比生物珊瑚早,2个月时修复效果优于生物珊瑚;3个月时,复合骨修复效果与自体骨无明显差别。结论:生物珊瑚、胶原和rhBMP-2复合人工骨能够引导和诱导新骨形成。  相似文献   

11.
In Vitro Evaluation of Five Core Materials   总被引:2,自引:0,他引:2  
PURPOSE: This in vitro study determined the fracture strength of five core materials supported by two different endodontic dowels. Diametral tensile strength and microhardness of the three resin composite core materials used in this study were also tested. MATERIAL AND METHODS: The fracture strength study used one lanthanide-reinforced flowable resin composite (Ti-Core Auto E), one titanium- and lanthanide-reinforced composite (Ti-Core), one lanthanide-reinforced composite (Ti-Core Natural), and two metal-reinforced glass ionomer core materials (Ketac Silver and GC Miracle Mix). Two types of dowels were used: a multitiered, split-shank threaded dowel with a flange (#1 Flexi-Flange) and one without a flange design (#1 Flexi-Post). The specimens were divided into ten groups. Each tooth/dowel and core specimen was placed in a special jig at 45 degrees and subjected to a load by a universal testing machine. The diametral tensile strength and the microhardness of the three resin composite core materials were measured by a universal testing machine and Barcol hardness tester, respectively. All test groups contained ten specimens. RESULTS: The fracture strength value of the resin composite core materials was significantly larger ( p < 0.0001) than those for the metal-reinforced glass-ionomer core materials. Analysis of variance (ANOVA) also showed that the Flexi-Flange dowel interacted with Ti-Core and Ti-Core Auto E to significantly ( p < 0.0013) increase the fracture strength relative to the Flexi-Post. One-way ANOVA revealed that there were no significant differences between them in terms of diametral tensile strength. The Barcol hardness values of the composite core materials were statistically different ( p < 0.0001), with the Ti-Core the highest, followed by Ti-Core Natural, then Ti-Core Auto E. CONCLUSIONS: Resin composite core material performed better than glass ionomer material in this in vitro study. The flowable composite core material performed about the same in terms of fracture strength and diametral tensile strength compared with nonflowable composites. Combined with certain core materials, the flange design increased the fracture strength of the tooth/dowel and core combination.  相似文献   

12.
目的:比较不同光固化复合树脂对瓷和树脂黏结强度的影响。方法:将3种光固化复合树脂黏固于经过表面处理的瓷表面,制成黏结试件,进行剪切强度测试。结果:Charisma、Esthet-X、AP-X三种树脂与瓷之间产生的黏结强度分别为15. 46、36. 39、25. 72MPa。结论:AP-X树脂与瓷之间的黏结性能较好,但对操作技术较为敏感。  相似文献   

13.
目的:探讨Estenia瓷树脂复合体的强度,并与其他几种树脂材料进行比较,为临床选择冠桥树脂材料提供参考。方法:采用Estenia瓷树脂复合体体外模拟下颌第一磨牙单冠和第一磨牙缺失3个单位固定桥的形态,测试单冠的抗压强度和固定桥的抗弯强度,并与Artglass、Solidex、Targis3种树脂材料在相同实验方法下测试得到的结果作比较。结果:Estenia瓷树脂单冠的折裂最大载荷均值为600.20N,Estenia瓷树脂桥的折裂最大载荷均值为302.53N。结论:Estenia瓷树脂复合体的强度高于Artglass﹑Solidex和Targis树脂复合体。  相似文献   

14.
目的:比较POSS复合树脂和三种临床常用复合树脂/聚合体弯曲强度和抗压强度,为POSS复合树脂的临床应用提供参考依据。方法:采用Zwick电子万能试验机分别测试试样的弯曲强度和抗压强度,以l.0mm/min的加载速度垂直加压直至试样破坏,记录破坏时的载荷,测试结果用SPSS16.0软件进行多样本均数方差分析(F检验)和SNK-q检验。结果:弯曲强度测试结果:FiltekTM Z250组最高,与其他三组间均有统计学差异;BeautifilII组好于POSS组和SureFil组(P〈0.05);POSS组与SureFil组间无显著性差异(P〉0.05)。抗压强度测试结果:FiltekTM Z250组最高,与其他三组间均有统计学差异;SureFil组好于POSS组和BeautifilII组(P〈0.05);POSS组和BeautifilII组间无显著性差异(P〉0.05)。结论:POSS复合树脂的弯曲强度和抗压强度可以满足临床应用需要。  相似文献   

15.
A growing number of composite materials are being used as an alternative for veneering cast restorations. The objective of this investigation was to evaluate and compare the shear bond strength of UDMA based composite, restorative composite, and heat cure acrylic when veneered to Ni–Cr alloy and to evaluate the type of bond failure. Three different veneering materials were used: heat cure acrylic, UDMA based composite and a restorative composite. 10 samples were fabricated, each with heat cure acrylic and restorative composite and 20 samples were fabricated with UDMA based composite; thus, the total number of samples amounted to 40. All the samples were subject to shear bond stress fracture tests and observed for the type of bond failure. The greatest mean shear bond strength was recorded in relation to the UDMA based composite material when thermal conducting paste was used during the curing (10.51 MPa). The mean bond strength values of UDMA based composite without thermal conducting paste (8.92 MPa), heat cured acrylic veneering material (4.24 MPa) and restorative composite material (5.03 MPa) were significantly different from each other (p > 0.05). Samples veneered with heat cure acrylic veneering material and restorative composite material showed adhesive failure. Samples prepared with UDMA based composite veneering composite showed cohesive or predominantly cohesive failure. UDMA based composite veneering material when used with heat protection paste exceeds the shear bond strength requirement as suggested by Matsumura et al. (>10 MPa). A statistically significant association between the test groups and the type of failure was observed.  相似文献   

16.
游离排骨肌皮复合组织瓣一期修复下颌骨及软组织缺损   总被引:1,自引:0,他引:1  
寻找一种既能满足下颌骨下软组织复合缺损重建需要,又不影响供区功能的新的修复材料。方法对10例各种原因所致的下颌骨及周围软组织员虱,采用游离腓骨肌皮复合组织瓣进行修复建建。  相似文献   

17.
PURPOSE: The study evaluates the compressive, flexural, and diametral tensile strengths of 8 core build-up materials from different material classes (highly viscous glass ionomer cement, autocured resin composite, and compomers). MATERIALS AND METHODS: All materials were manipulated according to the manufacturers' recommendations for use as core materials. At a temperature of 23.0 +/- 1.0 degrees C the properties of compressive, diametral tensile and flexural strength were determined using a universal testing machine at 15 minutes, 1 hour, and 24 hours after material preparation. Using one-way analysis of variance (ANOVA), multiple mean value comparisons were performed to determine significant differences (p< or =.05) between the core restoration materials. RESULTS: The values for compressive strength varied from 40.3 +/- 5.2 MPa (compomer) to 237.4 +/- 37.3 MPa (autocured resin composite) for the 3 measurement times. At 15 minutes, 1 hour, and 24 hours after first mixing, the ANOVA showed significant differences (p < or =.05) between the resin composite Core Paste and all of the other materials. Diametral tensile strengths ranged from 5.5 +/- 1.1 MPa for glass ionomer cement to 39.1 +/- 2.9 MPa for composite core material. Three-point flexural strength showed values ranging from 12.1 +/- 2.5 MPa for glass ionomer cement to 92.1 +/- 9.7 MPa for compomer between the 3 measurement times. CONCLUSIONS: Setting time influences the mechanical properties of the materials tested in this study. Autopolymerizing resin composite Core Paste demonstrated greater compressive and flexural strengths at the 3 measurement times than the other materials tested. Reinforced composites, in comparison to the autocured resin composites, yielded no improvement in tensile strength. Flexural and tensile strengths of the glass ionomer cement were lower than those of autocured resin composites and compomers.  相似文献   

18.
目的:检测新型纳米羟基磷灰石复合树脂与牙本质间的黏结强度,评价该材料对牙体组织的黏结性能。方法:健康离体磨牙36颗,随机分为3组,制作牙本质黏结面,分别黏结纳米羟基磷灰石复合树脂、复合树脂卡瑞斯玛、玻璃离子水门汀,经冷热交替试验后,测定各组试件的抗剪切力,计算剪切强度;体视显微镜下观察各组试件断裂界面断裂类型,采用SPSS17.0软件包对数据进行统计学分析。结果:纳米羟基磷灰石复合树脂的剪切强度为(11.23±4.6082) N/mm2,复合树脂卡瑞斯玛的剪切强度为(14.49±7.9855) N/mm2,玻璃离子水门汀的剪切强度为(10.08±6.3701) N/mm2,3组之间的抗剪切强度无显著差异;试件的黏结面断裂类型绝大多数为界面断裂,3组之间差异无显著性(P>0.05)。结论:纳米羟基磷灰石复合树脂作为一种新型牙体修复性材料,与牙体组织之间具有良好的黏结性能,达到了临床应用的要求。  相似文献   

19.
目的:研究不同种类树脂核材料与纤维桩的粘接性能.方法:用4 种树脂核材料(Multicore Heavy Body、LuxaCore、LIGHT-CORE、Z100)在纤维桩上分别制作桩核粘接试件,电子力学试验机测试抗拉强度,扫描电镜观察粘接界面.结果:不同树脂核材料与纤维桩的抗拉强度差异有显著性(P<0.05),其中LuxaCore粘接力均值最大,为(15.45±0.75) MPa;Z100粘接力最小,为(13.14±0.52) MPa.扫描电镜观察显示,Z100混合填料型复合树脂与纤维桩表面结合较差,结合界面有明显裂纹;LuxaCore双固化树脂核材料与纤维桩表面的结合较好,结合界面无明显裂纹.结论:树脂核材料种类对纤维桩树脂核粘接力有显著影响,流动性好的双固化树脂核材料(LuxaCore,Multicore Heavy Body)粘接性能优于光固化树脂核材料(LIGHT-CORE,Z100).  相似文献   

20.
目的:研究高强玻璃纤维含量对光固化型复合材料力学性能的影响。方法:通过改变预浸树脂基体中稀释剂的含量来改变复合材料中玻璃纤维的含量,通过烧结称重法测量玻璃纤维的含量,同时利用三点弯曲实验检测其力学性能,最终确定最佳纤维含量,即成型工艺中稀释剂的含量。结果:纤维含量为75.3%(树脂丙酮比为1:1.4)时,复合材料的三点弯曲强度达到最大值,其弯曲模量更接近牙本质。结论:玻璃纤维含量的提高可以增加光固化型复合材料的力学性能,使其弯曲模量更接近牙本质,但含量过高反而使其力学性能下降。  相似文献   

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