Objectives:Zirconia is becoming a prevalent material in *** any foreign bodies inserted may provide new niches for the bacteria in oral *** aim of this investigation was to explore the effect of surface properties inc...
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Objectives:Zirconia is becoming a prevalent material in *** any foreign bodies inserted may provide new niches for the bacteria in oral *** aim of this investigation was to explore the effect of surface properties including surface roughness and hydrophobicity on the adhesion and biofilm formation of streptococcus mutans(***),a primary pathogenic bacteria in dental caries.
目的:采用原子力显微镜(AFM)检测常见口腔链球菌属与不同表面粗糙度的光固化复合树脂及玻璃离子水门汀(GIC)之间的黏附力。方法:将光固化复合树脂和GIC样本表面梯度抛光,根据最终表面粗糙度不同分为300、200、100和10 nm组,使用AFM观察其表面形貌。采用先锋菌(血链球菌、缓症链球菌)和致龋菌(变异链球菌、表兄链球菌)制作细菌改性探针,通过AFM获得力—距曲线测量细菌与树脂和GIC样本表面的黏附力。对材料表面粗糙度测量值进行方差分析,细菌黏附力进行Kruskal-Wallis非参数检验,同时采用Dunn's进行组间两两比较,并对表面粗糙度与细菌黏附力进行相关性分析。结果:随材料表面粗糙度增加,细菌的黏附力增大,4种细菌的黏附力均在300nm的材料表面达到最大值;在10和300 nm组的GIC表面,血链球菌的的黏附力由0.875增加到3.698n N,变异链球菌的黏附力由0.578 n N增加到2.876 n N。4种细菌在树脂表面的黏附力略大于GIC,先锋菌的黏附力略大于致龋菌,组间差异均在200和300 nm组时较明显。结论:材料表面粗糙度对细菌黏附力的影响较大,二者有明显的相关性;GIC的抗菌性优于复合树脂;材料表面粗糙度对致龋菌的影响小于先锋菌。
Introduction Severely damaged and endodontically treated teeth need post-and-core *** of cast metal post-and-core are high fracture resistance self,good adaptation and change ability for tooth inclination but their di...
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Introduction Severely damaged and endodontically treated teeth need post-and-core *** of cast metal post-and-core are high fracture resistance self,good adaptation and change ability for tooth inclination but their disadvantages show the risk of root fracture,poor bonding *** fiber posts with tooth color have the similar elastic modulus with dentin and good biocompatibility but they can not be
目的:在负压技术运用于全酸蚀粘接系统,检测冷热循环老化对不同负压值下牙本质粘接强度的影响。方法:18颗无龋人类新鲜拔除前磨牙,用低速切割机平行冠中部咬合面切割使冠部牙本质暴露。18颗牙随机分为六组,分别命名为C、S6、S4、Ca、S6a和S4a。对照组C、Ca根据厂商说明处理(3M Single Bond 2)。实验组S6、S4、S6a、S4a分别用35%磷酸酸蚀15秒后,吹干,涂布粘接剂,然后用自制负压装置分别给予0.6(S6,S6a)、0.4(S4,S4a)大气压值,10s后解除负压、光照10秒,然后在上面堆积约6mm的树脂柱。C、S4和S6组36°C水浴24h后测试,而Ca、S4a和S6a进行冷热循环一万次老化处理。每颗牙切取三个试件(1×1×10mm),每组9个试件,进行微拉伸强度(μTBS)测试。结果:各组微拉伸强度分别为C=45.12±4.46 MPa;S4=84.36±21.80 MP和S6=93.36±9.59 MPa。老化后微拉伸强度分别为:Ca=25.22±5.85 MPa;S4a=51.43±10.58 MPa和S6a=58.21±9.46 MPa。冷热循环老化后微拉伸强度明显下降(P<0.05),但实验组μTBS仍高于老化前对照组μTBS。结论:负压技术可显著提高树脂牙本质粘接强度。虽然老化可使μTBS明显降低,但负压技术的应用仍可使牙本质粘接在老化后维持较高的粘接强度。
Fiber reinforced composites(FRCs)are increasingly used in dentistry with their tooth-matching mechanical,physical and aesthetic *** most commonly used FRC products consist of E-or S-glass fibers and methacrylate-based...
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Fiber reinforced composites(FRCs)are increasingly used in dentistry with their tooth-matching mechanical,physical and aesthetic *** most commonly used FRC products consist of E-or S-glass fibers and methacrylate-based resin *** commonly used methacrylate monomer bis-phenol A glycidyl methacrylate(bis-GMA)has a very high viscosity and possibly leads to a low degree of conversion(DC).In this study,the much less viscous urethane dimethacrylate
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