目的 ：比较5种不同表面处理方法对纤维桩黏结强度的影响。方法 ：50根纤维桩按照表面处理方法的不同,随机分为5组,A组为硅烷偶联剂组（Clearfil Porcelain Bond Activator,Kuraray）,B组为硅烷偶联剂＋黏结剂组（A＋Clearfil SE Bond,K...目的 ：比较5种不同表面处理方法对纤维桩黏结强度的影响。方法 ：50根纤维桩按照表面处理方法的不同,随机分为5组,A组为硅烷偶联剂组（Clearfil Porcelain Bond Activator,Kuraray）,B组为硅烷偶联剂＋黏结剂组（A＋Clearfil SE Bond,Kuraray）,C组为过氧化氢组（30%H2O2溶液）,D组为过氧化氢＋硅烷偶联剂组（C＋A）,E组为对照组。分别与树脂黏结剂黏结后,每组再平均分成2个小组,1组37℃生理盐水保存24 h后进行微拉伸强度测试,1组37℃生理盐水保存24 h后进行10000次冷热循环再进行微拉伸强度测试。采用SPSS17.0软件包对数据进行统计学分析。结果：冷热循环前A组-E组的微拉伸黏结强度分别为（6.7±0.7）、（14.4±1.1）、（10.7±0.9）、（16.0±1.0）和（6.7±1.0）MPa,冷热循环后,A组-E组的微拉伸黏结强度分别为（6.0±0.7）、（13.1±0.7）、（9.0±0.7）、（15.0±0.9）和（5.6±0.7）MPa。除硅烷偶联剂组与对照组之间外,其余各组之间差异均有显著性（P〈0.05）,其中,过氧化氢＋硅烷偶联剂组黏结强度最大。各组之间在冷热循环前、后的微拉伸黏结强度差异均有显著性（P〈0.05）。结论：温度疲劳循环可以降低5种表面处理的纤维桩与树脂间的黏结强度,30%H2O2溶液处理纤维桩后再使用硅烷偶联剂,可显著增加纤维桩与树脂之间的黏结强度。展开更多
The study of material damage and its physical mechanisms, the deep understanding of material performance degradation processes, and the improvement of key materials and devices used in a space environment are undoubte...The study of material damage and its physical mechanisms, the deep understanding of material performance degradation processes, and the improvement of key materials and devices used in a space environment are undoubtedly of critical scientific importance. This work investigated the mechanical properties and microstructures of the Ti-6Al-4V alloy subjected to thermocycling in a simulated low Earth orbit(LEO) space environment by using microhardness tests, X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. The results revealed an initial increase in hardness with the number of cycles, followed by a subsequent decrease. After 300 thermal cycles, many cavities were formed at the two-phase interface of the Ti-6Al-4V alloy. The dominating structures were transformed into dislocation cell substructures of larger size. After 500 cycles, the central structures in the sample were subgrains evolving by dislocation cells, as well as intragranular twins and jogs structures. The relationship between microstructural evolution and thermal fatigue in LEO space environment was discussed, which may help predict the fatigue damage of materials.展开更多
目的评价冷热循环对牙本质粘结系统与牙釉质粘结强度的影响。方法选取人离体下颌第三磨牙20颗,使用600目砂纸打磨颊面釉质,分别使用全酸蚀粘结系统AdperTM Single Bond2(SB2)、两步法自酸蚀粘结系统Clearfil SE Bond(CSE)、一步法自酸...目的评价冷热循环对牙本质粘结系统与牙釉质粘结强度的影响。方法选取人离体下颌第三磨牙20颗,使用600目砂纸打磨颊面釉质,分别使用全酸蚀粘结系统AdperTM Single Bond2(SB2)、两步法自酸蚀粘结系统Clearfil SE Bond(CSE)、一步法自酸蚀粘结系统ClearfilS3Bond(CS3)和iBondGI(IB)进行粘结。实验组冷热循环3000次后测定微拉伸粘结强度,对照组不做冷热循环处理直接测试。结果实验组冷热循环后,各粘结系统粘结强度均有所下降,但与对照组相比,仅IB有显著性差异(P<0.05)。对照组中SB2和CSE的粘结强度相近,明显高于CS3和IB。结论不同牙本质粘结系统与牙釉质的粘结强度存在差异。冷热循环3000次可导致一步法自酸蚀粘结系统IB与牙釉质粘结强度显著性下降。展开更多
Color stability of dental resin modified glass ionomer （RMGI） has been a challenge to dentistry; therefore, systematic changes in 2-hydroxyethyl methacrylate （HEMA） content were performed experimentally to find an...Color stability of dental resin modified glass ionomer （RMGI） has been a challenge to dentistry; therefore, systematic changes in 2-hydroxyethyl methacrylate （HEMA） content were performed experimentally to find an idea to enhance the color stability. Changes in color （△E＊ab） and color coordinates （△L＊, △a＊ and △b＊） of experimental 10-50 wt pct HEMA-added dental glass ionomers （HAGIs） and corresponding RMGIs were determined after 5000 cycles of thermocycling. Color changes of HAGIs were not influenced by the HEMA content while △L＊, △a＊ and △b＊ values were influenced by the HEMA content. Color stability of 30% or 40% HEMA-added HAGIs was not different from those of the commercial RMGIs. Since the influence of HEMA itself on the color stability of HAGIs was limited, compositional modification to increase the color stability of these materials should be developed.展开更多
文摘目的 ：比较5种不同表面处理方法对纤维桩黏结强度的影响。方法 ：50根纤维桩按照表面处理方法的不同,随机分为5组,A组为硅烷偶联剂组（Clearfil Porcelain Bond Activator,Kuraray）,B组为硅烷偶联剂＋黏结剂组（A＋Clearfil SE Bond,Kuraray）,C组为过氧化氢组（30%H2O2溶液）,D组为过氧化氢＋硅烷偶联剂组（C＋A）,E组为对照组。分别与树脂黏结剂黏结后,每组再平均分成2个小组,1组37℃生理盐水保存24 h后进行微拉伸强度测试,1组37℃生理盐水保存24 h后进行10000次冷热循环再进行微拉伸强度测试。采用SPSS17.0软件包对数据进行统计学分析。结果：冷热循环前A组-E组的微拉伸黏结强度分别为（6.7±0.7）、（14.4±1.1）、（10.7±0.9）、（16.0±1.0）和（6.7±1.0）MPa,冷热循环后,A组-E组的微拉伸黏结强度分别为（6.0±0.7）、（13.1±0.7）、（9.0±0.7）、（15.0±0.9）和（5.6±0.7）MPa。除硅烷偶联剂组与对照组之间外,其余各组之间差异均有显著性（P〈0.05）,其中,过氧化氢＋硅烷偶联剂组黏结强度最大。各组之间在冷热循环前、后的微拉伸黏结强度差异均有显著性（P〈0.05）。结论：温度疲劳循环可以降低5种表面处理的纤维桩与树脂间的黏结强度,30%H2O2溶液处理纤维桩后再使用硅烷偶联剂,可显著增加纤维桩与树脂之间的黏结强度。
基金supported by the Senior Talent Foundation of Jiangsu University(14JDG127)the Postdoctoral Foundation of Jiangsu province(1501159B)the open project program of Key Laboratory of Materials Modification by Laser,Ion and Electron Beams(Dalian University of Technology),Ministry of Education(LABKF1504)
文摘The study of material damage and its physical mechanisms, the deep understanding of material performance degradation processes, and the improvement of key materials and devices used in a space environment are undoubtedly of critical scientific importance. This work investigated the mechanical properties and microstructures of the Ti-6Al-4V alloy subjected to thermocycling in a simulated low Earth orbit(LEO) space environment by using microhardness tests, X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. The results revealed an initial increase in hardness with the number of cycles, followed by a subsequent decrease. After 300 thermal cycles, many cavities were formed at the two-phase interface of the Ti-6Al-4V alloy. The dominating structures were transformed into dislocation cell substructures of larger size. After 500 cycles, the central structures in the sample were subgrains evolving by dislocation cells, as well as intragranular twins and jogs structures. The relationship between microstructural evolution and thermal fatigue in LEO space environment was discussed, which may help predict the fatigue damage of materials.
文摘目的评价冷热循环对牙本质粘结系统与牙釉质粘结强度的影响。方法选取人离体下颌第三磨牙20颗,使用600目砂纸打磨颊面釉质,分别使用全酸蚀粘结系统AdperTM Single Bond2(SB2)、两步法自酸蚀粘结系统Clearfil SE Bond(CSE)、一步法自酸蚀粘结系统ClearfilS3Bond(CS3)和iBondGI(IB)进行粘结。实验组冷热循环3000次后测定微拉伸粘结强度,对照组不做冷热循环处理直接测试。结果实验组冷热循环后,各粘结系统粘结强度均有所下降,但与对照组相比,仅IB有显著性差异(P<0.05)。对照组中SB2和CSE的粘结强度相近,明显高于CS3和IB。结论不同牙本质粘结系统与牙釉质的粘结强度存在差异。冷热循环3000次可导致一步法自酸蚀粘结系统IB与牙釉质粘结强度显著性下降。
基金supported by the Korea Science and Engineering Foundation (KOSEF) Science Research Center grant funded by the Korean Ministry of Education,Science and Technology (MEST) through Bone Metabolism Research Center (No.0617-20080007)
文摘Color stability of dental resin modified glass ionomer （RMGI） has been a challenge to dentistry; therefore, systematic changes in 2-hydroxyethyl methacrylate （HEMA） content were performed experimentally to find an idea to enhance the color stability. Changes in color （△E＊ab） and color coordinates （△L＊, △a＊ and △b＊） of experimental 10-50 wt pct HEMA-added dental glass ionomers （HAGIs） and corresponding RMGIs were determined after 5000 cycles of thermocycling. Color changes of HAGIs were not influenced by the HEMA content while △L＊, △a＊ and △b＊ values were influenced by the HEMA content. Color stability of 30% or 40% HEMA-added HAGIs was not different from those of the commercial RMGIs. Since the influence of HEMA itself on the color stability of HAGIs was limited, compositional modification to increase the color stability of these materials should be developed.
