牙科着色氧化钇稳定四方多晶氧化锆陶瓷的制备及颜色性能

目的添加不同着色剂组合配制着色的牙科氧化钇稳定四方多晶氧化锆（3Y-TZP）陶瓷,并测定其颜色性能。方法将TZ-3Y-S粉体与一定组分的着色剂球磨混合后,在200 MPa压力下等静压成型,在1 500 ℃烧结2 h,烧制5种具有一定颜色的氧化锆材料,每个颜色组分别制备10 mm×10 mm×0.5 mm和10 mm×10 mm×1 mm着色氧化锆陶瓷片,在黑色背景下用柯尼卡美能达CM-2600d分光光度计进行颜色测定,并与VITA In-Ceram YZ染色液比色板颜色作比较。结果通过对粉体进行着色,配制出具有一定颜色的本体着色氧化锆陶瓷材料,颜色明度逐级降低,饱和度逐渐增大,2种厚度3Y-TZP陶瓷的颜色片色差较小,颜色空间范围是L*：67.76～77.78;a*：-2.19～3.80;b*：12.13～25.01。与VITA In-Ceram YZ染色液比色板相比,颜色空间近似,但明度的最低值仍较高。结论着色氧化锆陶瓷材料适宜用于临床上与饰面瓷颜色匹配,有必要再进一步研究低明度的着色氧化锆色片。     

牙科着色氧化锆陶瓷饰瓷前后的力学性能及断裂模式分析

目的:本研究对牙科氧化锆陶瓷着色及构筑饰面瓷前后的力学性能及断裂模式进行分析.方法:球磨混合一定组分的着色剂(氧化铁及氧化铈)和3Y-TZP(钇稳定氧化锆)粉体制备着色氧化锆陶瓷.根据ISO6872牙科陶瓷标准,制备着色和未着色氧化锆陶瓷的三点弯曲强度样品和构筑饰面瓷后的双层瓷样品,核心瓷与饰面瓷的厚度比为1:1.对所获得样品进行三点弯曲强度、断裂韧性和维氏硬度测试.采用X射线衍射(XRD)分析物相结构,扫描电镜(SEM)观察样品的断裂模式.结果:白色氧化锆陶瓷与着色氧化锆陶瓷的三点弯曲强度分别为1301 MPa和1203:MPa,统计学结果显示二者间没有明显差异,构筑饰面瓷后的三点弯曲强度分别为817 MPa和803 MPa,统计学结果显示二者间没有明显差异,但构筑饰面瓷后比单一材料样品强度降低,二者间有显著差异.在所有的双层瓷样品中,断裂模式的应力位移曲线显示为单峰断裂模式,断裂起始于核心瓷的张应力面中心区域同时发生饰面瓷的破碎和瓷层剥脱.结论:对氧化锆粉体的适当着色并没有明显影响材料的机械性能,着色和未着色氧化锆材料与饰面瓷具有良好的物理匹配性.     

牙科用Ce-Y-Mg复合稳定氧化锆增韧陶瓷的基本性能

目的 :探讨牙科用Ce -Y -Mg复合稳定氧化锆增韧陶瓷 (zirconiatoughenedceramic,ZTC)的基本性能。方法 :化学共沉淀法制备的三元复合稳定 (Ce-Y -Mg)氧化锆粉体造粒后 ,经双相干压成型 ,13 5 0℃烧结 ,磨光并抛光后测试其物理和力学性能。结果 :三元复合稳定 (Ce -Y -Mg)氧化锆增韧陶瓷烧结后密度为 6.0 1g/cm3,是理论密度的 98.5 2 % ,三点弯曲强度为 70 9Mpa ,断裂韧性为 11.6MPam1/2 。结论 :Ce -Y -Mg复合稳定剂可以对氧化锆陶瓷起到很好的增韧效果 ;Ce -Y -Mg复合稳定氧化锆增韧陶瓷强度高、韧性好 ,力学性能能够满足牙科桩钉标准。     

稀土氧化物着色牙色四方多晶氧化锆陶瓷的机械性能研究

目的探讨添加微量稀土氧化物对牙色四方多晶氧化锆（Y-TZP）陶瓷的机械性能的影响。方法以稀土氧化物（Pr6O11、CeO2、Er2O3）和过渡元素氧化物（MnO2）为着色剂,采用粉体掺杂方法在Y-TZP粉体中添加不同质量分数的着色剂,制备出6组牙色Y-TZP,测试其机械性能（包括弯曲强度、维氏硬度、断裂韧性）,并通过扫描电子显微镜观察各组陶瓷烧结体断裂面的显微结构,分析其断裂模式。结果6组牙色Y-TZP的弯曲强度为（792±20）～（960±17）MPa,断裂韧性为（4.72±0.31）～（5.64±0.38）MPam1/2,维氏硬度为（1 332±19）～（1 380±17）MPa;显微结构显示6组陶瓷均呈致密的多晶结构,断裂模式为混合型断裂。结论以稀土氧化物作为着色剂制备的Y-TZP具有较好的断裂韧性和维氏硬度,可满足口腔临床的应用要求。     

牙科渗透陶瓷用着色玻璃粉的制备与性能研究

目的:研究渗透陶瓷用着色玻璃粉的制备方法与相关性能。方法:将玻璃原料混匀烘干后放入氧化铝坩埚,在1400℃下熔融2h制成玻璃,测试玻璃的各种物理及力学性能。结果:差热分析显示玻璃的转换温度在690℃,在20℃-600℃之间,玻璃的热膨胀系数为6.2×10-6℃-1 ,密度2.23g/cm3,抗弯强度118Mpa,断裂韧性1.22Mpam1/2,维氏硬度7.4GPa。结论: 本研究所添加着色氧化物不影响渗透玻璃的物理及力学性能,制备的着色玻璃粉与多孔氧化铝预烧体有良好的物理与化学匹配性。     

牙科氧化锆纳米复合陶瓷的制备

目的:制备具有较好力学性能的口腔修复用纳米氧化锆复合陶瓷.方法:将纳米级3Y-ZrO2粉体以不同体积百分比加入3 Y-ZrO2造粒粉中,成型、烧结并测试不同纳米粉含量对试样力学性能的影响.结果:添加10%3Y-ZrO2纳米粉的试样力学性能最佳,其弯曲强度和断裂韧性分别达到(673.17±47.19)MPa,(9.01±0.82)MPa·m1/2.结论:纳米级3Y-ZrO2粉体的添加有一最适比例,本实验条件下为10%(V/V).     

牙科用Ce—Y—Mg复合稳定氧化锆增韧陶瓷的基本性能

目的：探讨牙科用Ce-Y-Mg复合稳定氧化锆增韧陶瓷（zirconia toughened ceramic,ZTC)的基本性能。方法：化学共沉淀法制备的三元复合稳定（Ce-Y-Mg）氧化锆粉体造粒后，经双相干压成型，1350℃烧结，磨光并抛光后测试其物理和力学性能。结果；三元复合稳定（Ce-Y-Mg）氧化锆增韧陶瓷烧结后密度为6.01g/cm^3，是理论密度的98．52％，三点弯曲强度为709Mpa，断裂韧性为11.6MPam^1/2。结论：Ce-Y-Mg复合稳定剂可以对氧化锆陶瓷起到很好的增韧效果；Ce-Y-Mg复合稳定氧化锆增韧陶瓷强度高，韧性好，力学性能能够满足牙科桩钉标准。     

烧结温度对牙科氧化锆增韧陶瓷性能的影响

目的 研究烧结温度对牙科氧化锆增韧陶瓷(zirconia toughened ceramic，ZTC)物理性能和弯曲强度的影响。方法 3％摩尔比的三氧化二钇(3mol％ Y2O3)稳定氧化锆粉体干压成型后，分别在1490℃、1530℃、1570℃、1610℃烧结，然后测试其密度、表面气孔率、线收缩率和弯曲强度。结果 从本项实验所得数据中可以看出，随着烧结温度的升高，氧化锆增韧陶瓷的密度和线收缩率呈上升趋势，表面气孔率呈下降趋势，弯曲强度呈现先上升后下降趋势。结论 在所设定的温度范围内，从烧结温度低和强度高的要求进行选择，3mol％ Y2O3稳定氧化锆增韧陶瓷的最佳烧结温度在1570℃左右。     

制备高性能氧化锆陶瓷牙科修复体的初步研究

目的 :本文对以氧化钇稳定四方相氧化锆 (Y -TZP)纳米微粉为原料 ,经部分烧结 -牙科计算机辅助设计/计算机辅助制造系统 (CAD/CAM)加工 -完全烧结三步法制备高性能的牙科修复体的工艺路线进行了初步探索。方法 :先经模压成型 ,低温烧结 ,制作了可供CAD/CAM加工的部分烧结Y -TZP陶瓷块 ;然后经牙科CAD/CAM机加工 ,得到初步的牙科修复体 ;最后对此修复体进行完全烧结 ,得到高性能的氧化锆牙科修复体。结果 :部分烧结的陶瓷块的切削性能优良 ,与CAD/CAM预期时间吻合。完全烧结的陶瓷材料机械性能优良 ,弯曲强度达到710MPa,断裂韧性达到 4 .77MPa·m1/ 2 。在完全烧结过程中 ,各个方向收缩均匀一致。得到的牙冠形态逼真 ,无裂纹。结论 :部分烧结 -CAD/CAM加工 -完全烧结三步法制备高性能的牙科修复体的工艺路线为一条切实可行的路线     

稀土氧化物着色牙色四方多晶氧化锆陶瓷的烧结性能

目的 探讨添加微量稀土氧化物对以稀土氧化物作为着色剂制备的与天然牙颜色匹配的牙色四方多晶氧化锆陶瓷的烧结性能的影响。方法 采用内着色法制备6组与天然牙色匹配的四方多晶氧化锆陶瓷,通过阿基米德定律测试其烧结致密性,通过扫描电镜观察其显微结构,X射线衍射测试其相变特征。结果 6组与天然牙色匹配的四方多晶氧化锆陶瓷的相对密度达到98%;电镜观察可见氧化锆的晶粒完整、晶界清楚、晶粒大小均匀,100～300 nm,未见异常生长的晶粒,晶界处未见到第二相的杂质相;XRD图谱显示,6种牙色四方多晶氧化锆陶瓷的晶相组成均以四方相氧化锆的特征峰为主,未见明显的杂质峰。结论 微量稀土氧化物的添加对以稀土氧化物作为着色剂制备的与天然牙颜色匹配的牙色四方多晶氧化锆陶瓷的烧结性能的影响较小,最终烧结体的主晶相仍以四方相为主。     

氧化锆和金属基底饰面瓷机械性能与微观结构的比较研究

目的比较分析氧化锆和金属基底饰面瓷的机械性能及微观结构。方法选择5种氧化锆基底饰面瓷Vintage ZR(ZR),Cerabien ZR(CZR),VitaVM9(VM9),Cercon ceram KISS(KISS),IPS e.max ceram(e.max)及烤瓷熔附金属用饰面瓷Vintage MP(MP)。每种饰面瓷各制作10个试件,测定表面粗糙度﹑三点弯曲强度(ISO 6872)和维氏硬度。计算断裂韧性。微观结构通过X射线衍射和扫描电镜分析。结果与其它饰面瓷相比,氧化锆基底用KISS的弯曲强度最高(P﹤0.05),CZR的弯曲强度最低(P﹤0.05);金属基底用MP的断裂韧性明显高于所有氧化锆用饰面瓷(P﹤0.001)。结论与氧化锆基底用饰面瓷相比较,金属基底用饰面瓷不易断裂,更具有临床可靠性。     

牙科氧化锆陶瓷的低温时效性能研究

目的 研究时效对5种牙科氧化锆陶瓷结构稳定性的影响.方法 5种氧化锆预烧结块(A组:TZ-3YS;B组:Vita In-Ceram YZ;C组:Ivoclar;D组:Cercon Smart;E组:Kavo)各切取15 mm×15 mm×1.5 mm氧化锆试件18片,常压致密烧结.时效处理如下:置于高温高压消毒炉中进行循环热处理,条件是134℃,0.2 MPa压力,维持时间为0h、1h、2h、3h、4 h、5h.X射线衍射分析(X-ray diffraction,XRD)试件的晶相结构,计算试件表面单斜相(m相)的相对含量.原子力显微镜观察A组和D组时效1、4 h的抛光试件.A组氧化锆再制备25 mm×4 mm×1.2 mm的试件30根,均分为未退火组(时效前)、退火组(时效前)和时效组(时效后),测试试件的三点弯曲强度.结果 除D组试件外,A、B、C、E组试件的m相含量均随时效时间的延长而增加,A组试件的m相含量最高,E组次之,B组和C组相近.XRD未检测到D组试件表面有m相,但使用原子力显微镜可观察到D组试件有m相晶核的成核和生长.时效前后A组试件的三点弯曲强度未衰减,未退火组试件三点弯曲强度[(1301±169)MPa]显著高于退火组[(1120±185)MPa]和时效组[(1158±111)MPa],差异有统计学意义(P＜0.05);而退火组与时效组间差异无统计学意义(P＞0.05).结论 牙科氧化锆陶瓷的低温时效效应具有时间依赖性,但时效效应并未使TZ-3YS的三点弯曲强度降低.     

���������ȫ�ɲ���

提要：氧化锆陶瓷是口腔修复材料研究热点,结合计算机辅助设计和计算机辅助制作（CAD／CAM）、粉浆涂塑等技术可以制作冠桥等修复体。本文将从微观结构和组成角度,对牙科常用氧化锆陶瓷种类、特点、美学效果和临床应用进展做一概述,供相关医务人员和科研工作者在从事氧化锆全瓷材料相关工作时参考。     

牙科氧化锆陶瓷压痕尺寸效应模型评价

目的:在分析现有氧化锆(Yttria partially stabilized zirconia,Y-TZP)陶瓷压痕尺寸效应规律和评价现有压痕尺寸效应模型基础上,推荐能准确描述Y-TZP陶瓷压痕尺寸效应的模型.方法:收集五种Y-TZP陶瓷压痕尺寸效应实验数据,回顾现有压痕尺寸效应模型,然后对现有压痕尺寸效应模型进行分...     

牙科陶瓷赫兹接触破坏研究

目的：比较两种牙科陶瓷赫兹动态加载下的破坏方式。方法：应用圆球加载实验对VitamarkⅡ可切削陶瓷和GI—Ⅱ渗透陶瓷标准试件进行动态加载,观测破坏方式。结果：渗透陶瓷中心塌陷,外侧放射状裂纹导致试件的破坏。切削陶瓷试件破坏来源于触点外侧的锥状裂纹和后续的放射状裂纹。结论：均质陶瓷赫兹接触破坏以跪性模式为主,而非均质陶瓷来源于类塑性破坏。     

Comparison of cell proliferation on modified dental ceramics

The aim of this study was to investigate the influence of substrate characteristics such as chemical composition and surface morphology of dental ceramics to support cell attachment and proliferation. Thus, body (B) and shoulder (S) porcelain differing on their surface morphology and composition were treated with oxides CaO or CaO and P(2)O(5) and four modified ceramics BCa, BCaP, SCa, SCaP were constructed, respectively. The modified ceramics differ from their controls concerning their surface morphology as evaluated by Scanning Electron Microscope (SEM), and their surface chemical composition (Na, KP and Ca) as evaluated by Energy Dispersing Spectroscopy (EDS). All modified ceramics support better than the control ceramics the cell proliferation over 72 h incubation period. Furthermore, higher rates of cell proliferation was detected in shoulder modified ceramics (SCa and SCaP) than in all other cases.     

Effects of multiple firings on the mechanical properties and microstructure of veneering ceramics for zirconia frameworks

Objectives

The purpose of this study is to evaluate the effects of multiple firings on the mechanical properties and microstructure of veneering ceramics used with zirconia frameworks.

Methods

Five different veneering ceramics for zirconia frameworks were used: Vintage ZR (ZR), Cerabien ZR (CZR), Vita VM9 (VM9), Cercon ceram KISS (KISS), IPS e.max ceram (e.max), and one veneering ceramic used for PFM frameworks: Vintage MP (MP). Twenty specimens were fabricated of each veneering ceramic. Ten specimens were fired twice and another ten specimens were fired ten times. Three-point flexural strength following the ISO 6872 and Vickers hardness were measured, and fracture toughness (K_IC) was calculated. Density and porosity were determined. Specimens were characterized using X-ray diffraction (XRD) and scanning electron microscopy (SEM).

Results

For all materials, density increased and porosity decreased after 10 firings. Significant differences in density and porosity were observed between 2 and 10 firings, with the exception of VM9 (P < 0.05). There were no significant differences in flexural strength between 2 and 10 firings except for MP. The Vickers hardness of ZR, VM9, KISS and MP increased significantly after 10 firings (P < 0.001). There were no significant differences in fracture toughness for ZR, CZR, VM9 and MP between 2 and 10 firings. However, e.max underwent a significant increase in fracture toughness (P = 0.000), and there was a significant decrease in the toughness of KISS after 10 firings (P = 0.007).

Conclusion

Multiple firings could be effective for improving the densification and the hardness of veneering ceramics for zirconia restorations.

Clinical significance

By 10 firings, the density and hardness of the veneering ceramics used with zirconia frameworks were raised, and porosity was reduced. However, no significant changes occurred in flexural strength, fracture toughness or microstructure.     

Graphene oxide‐based experimental silane primers enhance shear bond strength between resin composite and zirconia

Despite various mechanical and chemical surface‐pretreatment methods, long‐term bonding of resin composite to dental zirconia (ZrO₂) remains a major concern. In this study, graphene oxide (GO) sheets were infused into two commercially available primers and the enclosed mould shear bond strength (EM‐SBS) of resin composite to ZrO₂ was evaluated. Twelve fully sintered ZrO₂ blanks were pretreated and randomly allocated to four groups according to the primers used: RelyX (RX); GO blended RelyX (RXGO); Monobond‐S (MB); and GO blended Monobond‐S (MBGO). The resin composite stubs were bonded onto the pretreated ZrO₂ surfaces and analysed at baseline and after storage in distilled water for 2 and 4 months. The experimental primers blended with GO sheets influenced the surface morphology, visualized as increased surface roughness, and slightly increased the water contact angle measurements. Moreover, the infusion of primers with GO increased the mass fraction (wt%) of carbon and oxygen. The highest EM‐SBS values were found for RXGO, with mean (SD) EM‐SBS values of 26.4 (3.7) MPa and 21.5 (5.1) MPa after 2 and 4 months of storage, respectively. Infusion of silane primers with nanometre‐ to micrometre‐size GO sheets enhanced the SBS between resin composite and ZrO₂.     

Effect of artificial aging on high translucent dental zirconia: simulation of early failure

Higher yttria content enhances the translucency and appearance of dental zirconia materials. Alterations in material composition also affect mechanical properties. The aim of this study was to compare the fracture load after artificial short-term aging of monolithic, full-contour zirconia crowns with different amounts of yttria-stabilization. Sixty crowns (thirty super high translucent crowns (5Y-Z) and thirty high translucent crowns (3Y-Z)) were produced to fit a model of a premolar with a shallow chamfer preparation. The crowns were cemented with self-adhesive resin cement on composite abutments. For each zirconia type, three groups of crowns (n = 10) were allocated to: (i) cyclic loading (200 N, 1 Hz, 30,000 cycles), (ii) hydrothermal aging (3 × 20 min, 134°C 3.2 bar), or (iii) no treatment (control). Surviving crowns from the aging process were quasistatically loaded until fracture. The 3Y-Z crowns had statistically significantly higher fracture values (3,449 N) than the 5Y-Z crowns (1,938 N). The aging procedures did not affect load at fracture. Fractographic analysis showed that fractures started either at the crown margin or at the occlusal intaglio area. Higher yttria content leads to a reduction in material strength and damage tolerance, and this should be reflected in recommendations for clinical use.