不同膨胀系数石膏模型材料对树脂义齿表面粗糙度的影响研究

目的研究不同膨胀系数石膏模型材料对义齿表面粗糙度的影响。方法采用高、中、低三种不同膨胀系数的石膏模型材料,分别装埋型盒,各制作5个30 mm×10 mm×6.0 mm的树脂基托试样,测量其表面粗糙度。结果高、中、低膨胀系数石膏模型材料制作树脂试样表面粗糙度:轮廓算术平均偏差(Ra)值分别为(1.64±0.23)μm,(1.08±0.13)μm,(0.65±0.23)μm;微观不平高度(Rz)值分别为(6.44±1.12)μm,(5.18±0.96)μm,(3.35±0.95)μm,差别有统计学意义(P<0.01)。结论低膨胀系数石膏模型材料制作的树脂试料表面粗糙度值最低。     

四种加工方式对基托树脂力学性能的影响

目的 探讨不同混合和热加工方式对义齿基托树脂力学性能的影响,探讨捏炼混合+电烤箱加热的固化方式可否提高基托树脂的力学性能.方法 制作4组基托树脂试件,第1组:常规混合+水浴加热;第2组:捏炼混合+水浴加热;第3组:常规混合+电烤箱加热;第4组:捏炼混合+电烤箱加热.测定树脂的表面硬度、弯曲强度和弯曲模量、冲击强度.结果 第1～4组试件表面硬度分别为19.4、21.2、22.3、23.2 N/mm2,弯曲强度分别为58.58、63.32、66.73、63.76 MPa,冲击强度分别为1.42、1.53、1.77、1.78 KJ/m2,弯曲模量分别为2311.38、2417.82、2566.36、2400.37 MPa.结论 与常规混合+水浴加热方式相比,捏炼混合+电烤箱加热方式制作的树脂有较高的表面硬度和冲击强度,综合力学性能较佳.     

注塑基托树脂力学性能的检测

目的：对Vertex注塑基托树脂的力学性能进行研究,为临床开展注塑技术提供理论依据。方法：分实验对照两组,实验组为注塑基托树脂,对照组为临床常用热凝基托树脂,按照2种基托树脂的操作步骤要求进行试样制备,对不同基托树脂的试样在材料试验机上测定其冲击强度、弯曲强度、弹性模量和布氏硬度,并对断面进行电子显微分析。结果：注塑基托树脂和热凝基托树脂的冲击强度分别为6.01±0.50KJ/mm^3,7.35±0.93KJ/mm^3,（P〉0.05）,弯曲强度为104.44±3.07MPa,90.19±6.88MPa,（P〈0.05）,弹性模量为2.1±0.2GPa,2.4±0.1Gpa,（P〉0.05）,布氏硬度为12.17±0.93kg/mm^2,19.57±2.89kg/mm^2,（P〈0.05）;两种基托树脂的微观结构有明显不同,注塑基托树脂内部分布着许多粒径颗粒。结论：Vertex注塑基托树脂不仅具有热凝基托树脂的抗冲击能力,还具有良好的抗弯性能,韧性佳,是一种比较好的义齿基托树脂。     

微波聚合法对义齿基托树脂力学性能影响的研究

目的研究微波聚合方法对义齿基托树脂力学性能的影响。方法分别用微波聚合和水浴聚合方法制作63.0 mm×10.0 mm×2.5 mm的树脂试样各10个,经过10 000次冷热循环后,用电子万能试验机测量其弯曲强度和弯曲模量;同法制作同样规格的树脂试样各10个,用电子万能试验机测量其拉伸强度。结果微波法和水浴法制作的义齿基托树脂弯曲强度分别为（76.18±15.56）MPa和（73.06±13.01）MPa,差异无统计学意义（t=0.534 2,P〉0.05）;弯曲模量分别为（1 709.10±98.76）MPa和（1 699.21±90.23）MPa,差异无统计学意义（t=0.568 2,P〉0.05）;拉伸强度分别为（42.19±1.12）MPa和（44.35±1.22）MPa,差异无统计学意义（t=0.627 4,P〉0.05）。结论微波聚合方法制作的义齿基托树脂力学性能与水浴法制作的相当,但微波法聚合时间较水浴法明显缩短。     

不同膨胀系数石膏模型材料对树脂义齿精度影响的研究

目的 研究不同膨胀系数石膏模型材料对树脂义齿精度的影响.方法 采用高、中、低3种不同膨胀系数的石膏模型材料灌制上颌全口无牙颌标准模型各5个,并制作其上颌热凝甲基丙烯酸甲脂义齿,然后在相当于上颌第二磨牙远中部位处切断义齿基托与标准模型,以数字式万能显微镜测量上颌全口义齿基托组织面与标准模型之间共5个部位的距离.结果 高、中、低膨胀系数石膏模型材料制作的上颌义齿,精度分别在280～344μm,198～220μm 和 50～98μm之间,差别有高度统计学意义(P＜0.01).结论 低膨胀系数石膏模型材料制作的树脂义齿精度最高.     

4种义齿基托树脂力学性能比较

目的 :比较 4种义齿基托树脂的力学性能 ,为临床选择材料提供指导。方法 :按临床制作义齿的步骤制备试样 ,在材料试验机上测定材料的冲击强度、弯曲强度、弹性模量和布氏硬度 ,描绘弯曲试验的应力 应变曲线 ,并对断面进行显微分析。结果 :4种义齿基托树脂 (上海珊瑚、山西长治、Luciton199、Meliodent)的冲击强度分别为 (9.94± 2 .2 5)kJ/m2 、(6.55± 1.85)kJ/m2 、(13 .76± 4.3 1)kJ/m2 、(13 .70± 3 .71)kJ/m2 ,弯曲强度分别为 (75.2 7± 3 .2 4)MPa、(78.88± 7.66)MPa、(80 .47± 3 .2 7)MPa、(76.72± 3 .14 )MPa ,弹性模量分别为 (3 .0 8± 0 .15)GPa、(2 .96± 0 .10 )GPa、(2 .63± 0 .11)GPa、(2 .56± 0 .12 )GPa ,布氏硬度分别为(2 4.15± 1.3 4 )kg/mm2 、(2 3 .43± 1.65)kg/mm2 、(2 0 .86± 1.2 6)kg/mm2 、(18.49± 1.71)kg/mm2 。结论 :4种基托树脂材料相比 ,”上海珊瑚”和”山西长治”基托树脂硬而脆 ,Luciton 199基托树脂硬而强 ,Meliodent基托树脂硬而韧     

氧化锌晶须填料对义齿基托树脂力学性能的影响

目的：研究添加氧化锌晶须对基托树脂力学性能的影响。方法：将氧化锌晶须按不同的质量百分比加人基托粉中,分为空白对照组、1％、3％、5％、7％等5组。根据ISO标准测试各组的力学性能,并对试样断面进行扫描电镜观察。结果：随着氧化锌晶须用量的增加,复合材料的弯曲强度、弯曲弹性模量、显微维氏硬度呈先升后降的趋势。当氧化锌晶须用量为5％时,以上指标测得值最高,分别为（109．00±2．70）MPa、（3645．30±198．68）MPa、（20．57±0．85）kg／mm^2,树脂基托较对照组弯曲强度提高18．29％、弯曲弹性模量提高16．07％、显微维氏硬度提高29．94％。结论：氧化锌晶须填料显著增强了基托树脂的力学性能。     

喷砂结合化学处理对软衬材料粘结效果的影响

[摘要]目的：研究喷砂结合化学处理对硅橡胶软衬材料与基托树脂间粘结强度及基托树脂挠曲强度的影响。方法：制备48块30mm×10mm×7．5mm热凝聚甲基丙烯酸甲酯树脂块,每2个树脂块配成一个试件,24个试件随机分为4组,每组6个试件,即：（1）喷砂组：喷嘴与试件轻接触,采用250txm的氧化铝,在0．62MPa压力下喷砂30S;（2）喷砂＋丙酮组：粘结面喷砂处理同前,喷砂后的粘结面浸泡在丙酮溶液中30S;（3）喷砂＋甲基丙烯酸甲酯单体组（后简称单体）：粘结面喷砂处理同上,喷砂后的树脂块粘结面浸泡在甲基丙烯酸甲酯溶液中180S;（4）对照组：表面不处理。每个试件的两树脂块间衬以3mm厚的软衬材料,冷热循环5000次后,置于万能测试机上,以5mm／min的加载速度测试其拉伸粘结强度。另制备24块65mm×10mm×3．3mm长方体树脂块,分组及表面处理同前,涂布软衬材料粘结剂后测试挠曲强度。结果：喷砂组、喷砂＋丙酮组、喷砂＋甲基丙烯酸甲酯组及对照组试件的拉伸粘结强度分别为（1．31±0．45）MPa、（1．75±0．34）MPa、（1．96±0．50）MPa及（0．90±0．17）MPa。喷砂组与对照组间差别无统计学意义（P〉0．05）。喷砂＋丙酮组及喷砂＋单体组的拉伸粘结强度与对照组相比有统计学差异（P〈0．05）;喷砂＋丙酮组与喷砂＋单体组组间比较无统计学差异;四组间挠曲强度均无统计学差异（P〉0．05）。结论：喷砂结合化学处理树脂表面能增强硅橡胶软衬材料与基托树脂间的粘结强度,且对基托树脂挠曲强度没有影响。     

改性纳米氧化铈对义齿树脂基托机械性能的影响

目的:研究经硬脂酸改性后的纳米CeO₂对义齿树脂基托机械性能的影响。方法:将改性纳米颗粒按照质量比分别为1%、2%、3%、4%和5%的添加量添加到义齿基托材料(PMMA)的单体中,制成不同浓度的纳米齿复合材料,制成标准试件。对每组试件冲击强度,弯曲强度等指标进行检测,并与未添加纳米颗粒组比较,将最终数据进行统计分析。结果:经硬脂酸改性后的纳米氧化铈能够提高树脂基托的机械性能,所测试指标都呈现先增大后减小的趋势。其中添加比例为3%时纳米复合材料的综合性能达到最佳状态,其冲击强度、弯曲强度和弯曲模量分别为(4.186±0.149) J/cm²、(88.865±2.345) MPa和(1.539±0.096) GPa(P<0.05)。结论:在义齿基托材料单体中加入不同浓度的纳米氧化铈颗粒可以提高传统义齿基托的冲击强度,弯曲强度等机械性能,从而可以获得品质优良的纳米义齿复合材料。     

三种暂时冠桥树脂材料的力学性能研究

目的比较3种暂时冠桥树脂材料的力学性能,为临床选用材料提供实验参考。方法 3种被测试材料分别为半永久冠桥树脂材料LuxaCrown、普通冠桥树脂材料Protemp 4和MB自凝塑料。参照标准推荐的模具分别制备用于弯曲强度和弯曲模量测试用的条状试样(2.0mm×2.0mm×25mm),用于压缩强度测试用的圆柱状试样(直径4.0mm,高8mm)和用于断裂韧性测试的单边缺口梁试样(5.0mm×2.5mm×25mm,缺口深度2.5mm),每种材料制备各10个试样。在拉力试验机上以1.0mm/min的加载速度进行测试。结果 3种材料(LuxaCrown、普通冠桥树脂材料Protemp 4、MB自凝塑料)的弯曲强度分别为(110.35±10.94) MPa、(97.21±11.59) MPa、(49.43±11.63) MPa,弯曲模量分别为(2.46±0.17) GPa、(2.24±0.15) GPa、(2.09±0.19) GPa,压缩强度分别为(303.22±14.13) MPa、(279.21±12.54) MPa、(214.87±12.43) MPa,断裂韧度分别为(1.30±0.12)...     

树脂型氟离子缓释正畸粘接剂粘接性能的研究

目的　评价树脂型氟离子缓释正畸粘接剂的粘接性能 ,比较树脂型氟离子缓释正畸粘接剂 (FRA)和目前临床常用的两种正畸粘接剂的抗张粘接强度和抗剪粘接强度。方法　分别用 3种粘接剂在牛牙釉质上粘接金属托槽 ,在离体实验条件下 ,测试其抗张粘接强度和抗剪粘接强度并进行比较。结果　 3种粘接剂之间抗张粘接强度和抗剪粘接强度均没有统计学差异 (P >0 .0 5 ) ,且在 3个月的时间内 ,FRA中氟离子的释放没有对FRA的粘接强度产生不利的影响。结论　FRA可以达到临床使用的粘接强度要求。     

对四种粘接剂系统抗压强度及挠曲强度的评估

目的：对比研究4种粘接剂抗压强度及挠曲强度的差异.方法：选用树脂粘接剂Compolute,复合树脂Resinomer,树脂加强型玻璃离子Vitremer Luting及传统玻璃离子Ketac Cem4种粘接剂,分别制作抗压强度及挠曲强度的标准试件,每组10个.万能试验机测试其抗压强度及挠曲强度值,采用单因素方差分析及组间两两比较的LSD-t检验进行统计分析.结果：抗压强度组：Compolute为245.73±23.17MPa,Resinomer为153.50±18.59MPa,Vitremer Luting为61.89±10.92MPa,Ketac Cem为163.78±17.07 MPa.Ketac Cem和Resinomer组,其余各组组间两两比较差异均有统计学意义,P＜0.05.抗压强度由高到低的顺序为Compolute＞Ketac Cem＞Resinomer＞Vitremer Luting;挠曲强度组：Compolute为79.40±15.02MPa,Resinomer为102.18±19.61MPa,Vitremer Luting为20.70±3.89MPa,Ke切c Cem为21.04±4.02MPa.除后两组外,其余各组两两比较差异均有统计学意义,P ＜0.05.挠曲强度由高到低的顺序为Resinomer＞Compolute＞Ketac Cem＞Vitremer Luting.结论：与Vitremer Luting及Ketac Cem相比,Compolute表现较高的抗压强度及挠曲强度,Resinomer则具有较高的挠曲强度及较低的抗压强度,临床上可根据不同修复需求选择合适的粘接系统.     

添加纳米聚膦腈对聚氨酯材料力学强度的影响

目的 研究添加纳米聚膦腈对聚氨酯材料力学强度的影响。方法 将3种实验组材料（纯聚氨酯材料（PU）、含1%纳米聚膦腈的聚氨酯材料（1% PSZ-PU）、含5%纳米聚膦腈的聚氨酯材料（5% PSZ-PU））以及对照组自固化型硅橡胶软衬材料,分别经历0次、1 000次、3 000次冷热循环后测试其拉伸强度和撕裂强度,并进行统计学分析。结果 冷热循环0次、1 000次、3 000次后3种聚氨酯复合材料拉伸强度依次为：PU组32.85 MPa、23.09 MPa和24.36 MPa;1% PSZ-PU组34.98 MPa、25.33 MPa和25.52 MPa;5% PSZ-PU组32.29 MPa、28.22 MPa和26.10 MPa。撕裂强度依次为：PU组40.64 kN/m、37.96 kN/m和40.69 kN/m;1% PSZ-PU组40.87 kN/m、41.01 kN/m和40.63 kN/m;5% PSZ-PU组42.73 kN/m、43.28 kN/m和41.59 kN/m,它们均大于对照组硅橡胶材料的拉伸强度和撕裂强度,其中实验组材料组间比较时,除循环1 000次后,5% PZS-PU和1% PZS-PU的拉伸强度差异具有统计学意义（P<0.05）外,其他循环次数中3组实验组材料组间的拉伸强度和撕裂强度的差异均无统计学意义（P>0.05）。结论 3组聚氨酯复合材料的拉伸强度和撕裂强度均高于对照组硅橡胶类软衬材料,5%以内的聚膦腈纳米球添加剂量未对聚氨酯的拉伸强度和撕裂强度产生明显的增强作用。     

Estenia瓷树脂复合体制作冠桥的强度测试

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。     

Strength of Denture Base Resins Repaired with Auto- and Visible Light-Polymerized Materials

Purpose: Clinicians are still confused about the choice of repair method, which depends on factors such as the length of time required for processing, the mechanical strength of the repaired material, and the effect of stress concentration in the acrylic resins before the repair. The aim was to determine the impact and flexural strength characteristics, such as stress at yield, Young's modulus, and displacement at yield of denture base resins fractured and repaired by three methods using heat‐, auto‐, and visible light‐polymerized acrylic resins. Material and Methods: For impact and flexural strength tests, 18 rectangular specimens measuring 50 × 6 × 4 mm³ and 64 × 10 × 3.3 mm³, respectively, were processed using Impact 2000, Lucitone 550, Impact 1500, and QC‐20 acrylic resins. Fracture tests were performed according to ISO1567:1999. Afterward, all fractured specimens were stored in distilled water at 37°C for 7 days, and then repaired with (1) the same acrylic resin used for specimen fabrication (n = 6), (2) an autopolymerized acrylic resin (TruRepair, n = 6), and (3) a visible light acrylic resin (Versyo.com, n = 6). The repaired specimens were again submitted to the same fracture tests, and the failures were classified as adhesive or cohesive. Data from all mechanical tests after repair by the different methods were submitted to two‐way ANOVA, and mean values were compared by the Tukey test. Results: All acrylic resins showed adhesive fractures after impact and flexural strength tests. Differences (p < 0.05) were found among repair methods for all acrylic resins studied, with the exception of displacement at yield, which showed similar values for repairs with auto‐ and visible light‐polymerized acrylic resins. The highest values for impact strength, stress, and displacement at yield were obtained when the repair was made with the same resin the specimen was made of. Conclusion: Denture base acrylic resins repaired with the same resin they were made of showed greater fracture strength.     

Diametral tensile and compressive strengths of several types of core materials.

PURPOSE: Compressive and diametral tensile strengths (DTSs) of core materials are thought to be important, because cores usually replace a large bulk of tooth structure and should provide sufficient strength to resist intraoral tensile and compressive forces. This study was undertaken to compare the mechanical properties of materials used for direct core foundations. MATERIAL AND METHODS: The differences between the compressive and DTSs of six core materials, including Duralloy (high-copper amalgam), Grandio (visible light-cured nanohybrid resin composite), Admira (organically modified ceramic), Filtek P60 (packable composite resin), Rebilda DC (dual-cure adhesive core material), and Argion Molar (silver-reinforced glass ionomer cement), were tested. A total of 120 specimens, half for the compressive strength (CS) test (6 mm in height, 4 mm in diameter) and the other half for the DTS test (6 mm in diameter, 3 mm in thickness), were prepared. The specimens were stored at room temperature in distilled water for 7 days. The Lloyd testing machine was used to load the specimens at a crosshead speed 0.5 cm/min, and the strength values were determined in MPa. RESULTS: The compressive and DTS test values (in MPa), respectively, of the materials were: Admira (361, 44); Filtek P60 (331, 55); Grandio (294, 53); Rebilda DC (279, 42); Duralloy (184, 40); and Argion Molar (107, 9). Kruskal-Wallis test was computed, and multiple comparisons test discerned many differences among materials (p < 0.05). CONCLUSION: Packable composite resin (Filtek P60), visible light cured nanohybrid resin composite (Grandio), and organically-modified ceramic (Admira) had higher compressive and DTS values than the other materials.     

Laboratory strength of glass ionomer and zinc phosphate cements

PURPOSE: The present in vitro study examined 3 mechanical properties, namely compressive, flexural, and diametral tensile strength, of various commercially available cements and core materials as a function of time after mixing. MATERIALS AND METHODS: The examined materials were 2 cermet cements (Ketac Silver [ESPE, Seefeld, Germany] and Chelon Silver [ESPE]), 1 metal-reinforced glass ionomer cement (Miracle Mix [GC Dental Industrial Corp, Tokyo, Japan]), 2 conventional glass ionomer cements (Ketac Bond [ESPE] and Ketac Cem [ESPE]), 1 standard cure zinc phosphate cement (Harvard Cement [Richter and Hoffmann, Berlin, Germany]), and 1 zinc phosphate cement with the addition of 30% silver amalgam alloy powder (Harvard Cement 70% with Dispersalloy 30% [Richter and Hoffmann/Johnson and Johnson, East Windsor, NJ]). Properties were measured using a universal testing machine at 15 minutes, 1 hour, and 24 hours after first mixing. RESULTS: Compressive strengths varied widely between the 3 times of measurement from 5.8 +/- 6.6 MPa for Ketac Cem to 144.3 +/- 10.2 MPa for Ketac Silver. Twenty-four hours after mixing, the Bonferroni test showed significant (p 相似文献   

Flexural strength of veneering ceramics for zirconia

OBJECTIVES: The flexural strengths of veneering ceramics for zirconia were compared. METHODS: With 10 different veneering ceramics for zirconia (test group) and three different veneering ceramics for the metal-ceramic technique (control group) three-point flexural strength and biaxial flexural strength according to ISO 6872: 1995 as well as four-point flexural strength according to EN 843-1: 2005 were measured (n=10). Statistical analysis was performed with one-way ANOVA and post hoc Scheffé test (SPSS, p<0.05). RESULTS: For the test group, three-point flexural strength ranged between 77.8+/-8.7 and 106.6+/-12.5MPa without any statistically significant differences, biaxial flexural strength between 69.1+/-4.8 and 101.4+/-10.5MPa with three homogeneous groups and four-point flexural strength between 59.5+/-6.2 and 89.2+/-9.5MPa with five homogeneous groups. The control group showed three-point flexural strength values ranging from 93.3+/-13.5 to 149.4+/-20.5MPa, biaxial flexural strength values from 93.4+/-10.0 to 141.2+/-11.6MPa, and four-point flexural strength values from 82.7+/-8.5 to 116.9+/-9.8MPa. In every case, the results of the four-point flexure test were significantly lower than those obtained in the three-point flexure test. The three-point flexural strengths of the test group are similar to those of two ceramics of the control group. The flexural strength of one ceramic of the control group significantly exceeded the strengths of all other ceramics investigated. CONCLUSION: Three-point flexural strength values of veneering ceramics for zirconia are similar to those of veneering ceramics for the metal-ceramic technique. The four-point flexure test among all three tests showed highest discrimination between the different ceramic materials.     

二期热压处理对Artglass玻璃瓷抗压强度和直径拉伸强度的影响

目的:探讨二期高温高压处理对Artglass玻璃瓷材料机械性能的影响。方法:用Artglass DA3材料分别制作20个抗压强度和直径拉伸强度测试试件,所有试件在UniXS频闪聚合机中常规聚合,而后随机分为两组,一组为对照组,另一组用国产自控多用途牙用树脂聚合器进行二期热压处理,温度120℃,压力0.6Mpa,时间7min;用Instron1195万能拉力测试仪测得抗压强度和直径拉伸强度,对二期热压处理前后的测试值用单因素方差分析方法进行比较。结果:二期热压处理后Artglass的抗压强度和直径拉伸强度都有了显著提高,提高幅度分别为16%和9%(P<0.01)。结论:二期热压处理可以明显提高Artglass玻璃瓷材料的抗压强度和直径拉伸强度。     

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目的研究无机填料含量对流动树脂的挠曲强度和压缩强度的影响。方法于2012年4月在北京大学口腔医学院口腔材料研究室测定Clearfil Flow、Filtek Flow、DenFil Flow、Filtek Z250复合树脂无机填料的质量分数、挠曲强度和压缩强度。结果流动树脂中无机填料的质量分数与其挠曲强度的变化顺序相一致,由小到大依次为DenFil Flow、Filtek Flow、Clearfil Flow、Filtek Z250。DenFil Flow与其余3组间挠曲强度差异均有统计学意义（P〈0.05）,Filtek Flow与Clearfil Flow、Filtek Z250间挠曲强度差异亦均有统计学意义（P〈0.05）,但Clearfil Flow与Filtek Z250间挠曲强度差异无统计学意义（P〉0.05）。4种材料压缩强度差异均无统计学意义（P〉0.05）。结论高填料型流动树脂的挠曲强度远高于普通流动树脂,并且可达到我国医药行业标准规定面修复材料的要求;压缩强度与前后牙通用树脂相近,可以满足临床应用的需要。