The aim of this work was to investigate by X-ray photoelectron spectroscopy the effect of high pressure on the chemical environments of Si 2p, O 1s and Li 1s in lithium disilicate glass ceramic with stoichiometric com...The aim of this work was to investigate by X-ray photoelectron spectroscopy the effect of high pressure on the chemical environments of Si 2p, O 1s and Li 1s in lithium disilicate glass ceramic with stoichiometric composition Li2O·2SiO2 (LS2). A group of samples was processed at 2.5 GPa, 4 GPa and 7.7 GPa at room temperature and a second group was crystallized under high pressure and high temperature. Large shifts of the binding energy toward higher energies were observed in the X-ray photoelectron spectroscopy spectra for samples of the first group after densification at 2.5 and 4 GPa. For samples processed at 7.7 Gpa, the major component of the binding energy for the Si 2p environment remained practically unchanged compared to the pristine sample but new components, with smaller intensities, appeared in the spectra, indicating the existence of distinct Q-species induced by high pressure. This behavior may be related to changes in the number of bridged and non-bridged oxygen atoms in the glass structure. The results for the second group of samples, crystallized under high pressure, showed evidences of three binding energies for the O atoms, one of them related to non-bridged and two of them to bridged O atoms.展开更多
目的评估一种通用粘接剂对于3种不同类型的CAD/CAM可切削材料的短期粘接成绩。方法制作氧化钇稳定四方相氧化锆陶瓷、纳米复合陶瓷和二硅酸锂玻璃陶瓷试件各20枚,其中前两者进行喷砂处理,后者进行氢氟酸酸蚀处理。各组陶瓷再分为2个亚组...目的评估一种通用粘接剂对于3种不同类型的CAD/CAM可切削材料的短期粘接成绩。方法制作氧化钇稳定四方相氧化锆陶瓷、纳米复合陶瓷和二硅酸锂玻璃陶瓷试件各20枚,其中前两者进行喷砂处理,后者进行氢氟酸酸蚀处理。各组陶瓷再分为2个亚组,分别使用(SBU)或不使用(Ctr)通用粘接剂Single Bond Universal。以上表面处理瓷片与复合树脂柱通过树脂水门汀粘接,制作粘接试件,37℃水储24 h后测试剪切粘接强度并记录断裂模式。喷砂处理的氧化锆陶瓷和纳米复合陶瓷,以及酸蚀处理的二硅酸锂玻璃陶瓷通过扫描电镜(SEM)观察表面微观形态。结果 SEM观察显示酸蚀处理的二硅酸锂玻璃陶瓷,喷砂处理的氧化锆陶瓷和纳米复合陶瓷相对于粗化处理前呈现出粗糙的表面形态。3种经粗化处理的材料使用通用粘接剂表面处理后,剪切强度较未使用者显著增强。结论通用粘接剂Single Bond Universal能够增强氧化钇稳定四方相氧化锆陶瓷、纳米复合陶瓷和二硅酸锂玻璃陶瓷3种类型CAD/CAM可切削材料的短期粘接强度。展开更多
The novel dental ceramics can be fabricated at lower temperatures when sol-gel derived lithium disilicate glass ceramics(LDGC)was used as an additive for yttria stabilized tetragonal zirconia polycrystalline(Y-TZP)cer...The novel dental ceramics can be fabricated at lower temperatures when sol-gel derived lithium disilicate glass ceramics(LDGC)was used as an additive for yttria stabilized tetragonal zirconia polycrystalline(Y-TZP)ceramics.The effect of LDGC on the sintering,mechanical,and translucent properties of Y-TZP ceramics was investigated in the present study.The results showed that the LDGC additive effectively improved the densification of Y-TZP at 1100℃,which was much lower than the sintering temperature for pure Y-TZP.When sintered at 1100℃,the Y-TZP with 1 wt%LDGC reached a relative density of 95.45%,and prossessed a flexural strength of 482.4 MPa and a fracture toughness of 5.94 MPa-m12.Moreover,its translucency was also improved.While,the addition of LDGC could result in an escape of yttrium atoms from the grain lattice of zirconia,which induced the tetragonal-monoclinic transformation of zirconia and abnormal growth of monoclinic grains.The escaped yttrium atoms diffused into the intergranular glass phase.The results indicated that the novel Y-TZP-LDGC ceramics has a great potential to be used for all-ceramic restorations.展开更多
目的研究不同全瓷材料由同一种CAD/CAM系统制作后其边缘适合性的差异,观察不同材料在烧结、结晶、上釉前后的边缘适合性变化,为临床选择全瓷材料提供一定的参考依据。方法制作前磨牙牙备后树脂试件,分别使用长石类全瓷材料,二硅酸锂全...目的研究不同全瓷材料由同一种CAD/CAM系统制作后其边缘适合性的差异,观察不同材料在烧结、结晶、上釉前后的边缘适合性变化,为临床选择全瓷材料提供一定的参考依据。方法制作前磨牙牙备后树脂试件,分别使用长石类全瓷材料,二硅酸锂全瓷材料和氧化锆全瓷材料在Sirona in Lab CAD/CAM系统中制作全瓷修复体各8个,在体视显微镜下观察各冠边缘与试件间隙。结果在基底冠和全冠两个阶段的边缘间隙,长石类分别为(59.18±8.15)μm和(59.78±8.47)μm,二矽酸锂类分别为(56.16±6.64)μm和(57.22±7.45)μm,氧化锆类分别为(18.12±4.69)μm和(22.36±4.48)μm。其中,长石类与二矽酸锂类的边缘间隙差异无统计学意义(P>0.05),但他们与氧化锆类比较,差异有统计学意义(P<0.05)。而同组的修复体在两阶段的数据差异均无统计学意义(P>0.05)。结论三种材料制作的全冠适合性均在临床可接受的范围内,但氧化锆组更接近美国牙科协会的标准,值得推广应用。展开更多
文摘The aim of this work was to investigate by X-ray photoelectron spectroscopy the effect of high pressure on the chemical environments of Si 2p, O 1s and Li 1s in lithium disilicate glass ceramic with stoichiometric composition Li2O·2SiO2 (LS2). A group of samples was processed at 2.5 GPa, 4 GPa and 7.7 GPa at room temperature and a second group was crystallized under high pressure and high temperature. Large shifts of the binding energy toward higher energies were observed in the X-ray photoelectron spectroscopy spectra for samples of the first group after densification at 2.5 and 4 GPa. For samples processed at 7.7 Gpa, the major component of the binding energy for the Si 2p environment remained practically unchanged compared to the pristine sample but new components, with smaller intensities, appeared in the spectra, indicating the existence of distinct Q-species induced by high pressure. This behavior may be related to changes in the number of bridged and non-bridged oxygen atoms in the glass structure. The results for the second group of samples, crystallized under high pressure, showed evidences of three binding energies for the O atoms, one of them related to non-bridged and two of them to bridged O atoms.
文摘目的评估一种通用粘接剂对于3种不同类型的CAD/CAM可切削材料的短期粘接成绩。方法制作氧化钇稳定四方相氧化锆陶瓷、纳米复合陶瓷和二硅酸锂玻璃陶瓷试件各20枚,其中前两者进行喷砂处理,后者进行氢氟酸酸蚀处理。各组陶瓷再分为2个亚组,分别使用(SBU)或不使用(Ctr)通用粘接剂Single Bond Universal。以上表面处理瓷片与复合树脂柱通过树脂水门汀粘接,制作粘接试件,37℃水储24 h后测试剪切粘接强度并记录断裂模式。喷砂处理的氧化锆陶瓷和纳米复合陶瓷,以及酸蚀处理的二硅酸锂玻璃陶瓷通过扫描电镜(SEM)观察表面微观形态。结果 SEM观察显示酸蚀处理的二硅酸锂玻璃陶瓷,喷砂处理的氧化锆陶瓷和纳米复合陶瓷相对于粗化处理前呈现出粗糙的表面形态。3种经粗化处理的材料使用通用粘接剂表面处理后,剪切强度较未使用者显著增强。结论通用粘接剂Single Bond Universal能够增强氧化钇稳定四方相氧化锆陶瓷、纳米复合陶瓷和二硅酸锂玻璃陶瓷3种类型CAD/CAM可切削材料的短期粘接强度。
基金supported by the Shanghai Committee of Science and Technology,China(No.17441904100).
文摘The novel dental ceramics can be fabricated at lower temperatures when sol-gel derived lithium disilicate glass ceramics(LDGC)was used as an additive for yttria stabilized tetragonal zirconia polycrystalline(Y-TZP)ceramics.The effect of LDGC on the sintering,mechanical,and translucent properties of Y-TZP ceramics was investigated in the present study.The results showed that the LDGC additive effectively improved the densification of Y-TZP at 1100℃,which was much lower than the sintering temperature for pure Y-TZP.When sintered at 1100℃,the Y-TZP with 1 wt%LDGC reached a relative density of 95.45%,and prossessed a flexural strength of 482.4 MPa and a fracture toughness of 5.94 MPa-m12.Moreover,its translucency was also improved.While,the addition of LDGC could result in an escape of yttrium atoms from the grain lattice of zirconia,which induced the tetragonal-monoclinic transformation of zirconia and abnormal growth of monoclinic grains.The escaped yttrium atoms diffused into the intergranular glass phase.The results indicated that the novel Y-TZP-LDGC ceramics has a great potential to be used for all-ceramic restorations.
文摘目的研究不同全瓷材料由同一种CAD/CAM系统制作后其边缘适合性的差异,观察不同材料在烧结、结晶、上釉前后的边缘适合性变化,为临床选择全瓷材料提供一定的参考依据。方法制作前磨牙牙备后树脂试件,分别使用长石类全瓷材料,二硅酸锂全瓷材料和氧化锆全瓷材料在Sirona in Lab CAD/CAM系统中制作全瓷修复体各8个,在体视显微镜下观察各冠边缘与试件间隙。结果在基底冠和全冠两个阶段的边缘间隙,长石类分别为(59.18±8.15)μm和(59.78±8.47)μm,二矽酸锂类分别为(56.16±6.64)μm和(57.22±7.45)μm,氧化锆类分别为(18.12±4.69)μm和(22.36±4.48)μm。其中,长石类与二矽酸锂类的边缘间隙差异无统计学意义(P>0.05),但他们与氧化锆类比较,差异有统计学意义(P<0.05)。而同组的修复体在两阶段的数据差异均无统计学意义(P>0.05)。结论三种材料制作的全冠适合性均在临床可接受的范围内,但氧化锆组更接近美国牙科协会的标准,值得推广应用。
