【作者】 周黎；

【导师】 骆小平；

【作者基本信息】 南京大学 ， 口腔临床医学， 2012， 硕士

【摘要】 近年来,随着生活条件的改善,因烤瓷修复的美观局限性和金属离子引起的致敏作用,使得全瓷材料在口腔临床固定修复中脱颖而出。随着工业与科技的进步,较多美观性与生物相容性好的全瓷材料被用于临床,主要是受力低的前牙区；由于陶瓷是脆性材料,后牙区修复体对材料性能要求较高,曾一度制约着全瓷材料的发展。上世纪九十年代以后,氧化锆被引进口腔作为固定修复体的内冠,除具备全瓷材料的生物相容性好、稳定性高、有一定美学效果外,高弯曲强度和高断裂韧性成为其的显著优点。由于氧化锆主要是由致密的晶相构成,几乎不含有玻璃相,美学效果较差,且硬度极高,为模拟天然牙的美学效果和降低对颌天然牙的磨损,因此需在其表面饰瓷。随着CAD/CAM技术用于制作氧化锆陶瓷内冠后,氧化锆双层全瓷修复体在临床中开始广泛试用,然而较多研究统计发现,其失败率显著高于传统的金瓷修复体。主要失败原因有：饰瓷剥脱、修复体边缘的继发龋的发生等。为解决饰瓷剥脱问题,众多研究从材料的改进、结合界面的分析、有限元应力分析等各角度寻求方案,进行各种体外试验研究。随着工艺技术进步,材料与工艺的改进能否改善氧化锆与饰瓷的结合,也成为近来研究如何降低失败率的方案之一。[目的]本研究通过体外剪切试验和界面显微形貌观察,来探讨饰瓷工艺对氧化锆与表面饰瓷结合强度的影响,并分析不同工艺饰瓷与氧化锆结合界面的差异。[方法]本研究,实验组选择两品牌氧化锆分别与两种工艺饰瓷结合,分别为IPS e.max ZirCAD/IPS e.max ZirPress (EP组),IPS e.max ZirCAD/IPS e.max Ceram (EV组),Incoris ZI/IPS e.max ZirPress (IP组),Incoris ZI/IPS e.max Ceram (IV组)。对照组选择镍铬合金分别与两种工艺体瓷结合：Wiron99/IPS InLine POM (NP组)和Wiron99/IPS InLine (NV组)。各组中随机抽取一半试件,进行冷热循环20000次。万能试验机测试剪切强度,体式显微镜观察断面。场发射扫描电镜观察交界面,采用X线能谱分析测试交界面处元素含量的变化。[结果]1.冷热循环前,NP组、NV组的结合强度值与EP组无显著差异(P>0.05),高于EV组、IP组和IV组(P<0.05),EP组结合强度值显著高于IV组(P<0.05),而其他各组间无显著性差异(P>0.05)。冷热循环后,NV组的结合强度值显著高于EV组、IP组和IV组(P<0.05),而NP组显著高于EV组、IV组(P<0.05)。各组内的冷热循环前后剪切强度值间无显著性差异(P>0.05)。2.断裂模式：体式显微镜观察氧化锆基底表面,热压铸组主要是粘结性失败模式；粉浆涂塑组主要是内聚性失败模式。镍铬合金基底表面,均表现为从体瓷到氧化层的混合性失败模式。3.扫描电子显微镜观察交界面：EP组结合界面图,二者结合较紧密,但交界面处可见部分气孔缺陷,而EV组在交界面处和饰瓷内部可见较多的气孔缺陷。NP组结合界面图,InLine POM与OP交界面结合紧密,InLine POM内较致密,但OP内可见较多气孔缺陷,而且OP与NiCr交界面间存在部分气孔缺陷。4.EDS分析交界面两侧的元素渗透情况：EP组交界面两侧的元素比例变化,从ZirPress侧向ZirCAD侧,ZirPress层中的Si元素逐渐减少,渗透约2-3μm。NiCr与OP交界面两侧的元素比例变化,从OP侧向NiCr侧,OP层中的Zr元素、Si元素逐渐减少,渗透约2-3μm。[结论]1.相比本研究中其他组氧化锆饰瓷的结合,ZirCAD与表面热压铸瓷ZirPress的结合较好,可满足临床应用要求,有望降低氧化锆的临床失败率。2.临床上氧化锆、金属合金内冠表面可使用热压铸饰瓷工艺,既降低饰瓷材料缺陷,又提高饰瓷工艺效率。3.模仿口内两年的热疲劳耐久性处理,对氧化锆表面饰瓷体外结合强度几乎无影响。更多还原

【Abstract】 With the improvement of living level, all-ceramics materials have become to be the alternative restoration materials, because of the limited esthetics and allergist by metal ions. With the advancement of industry and technique, more and more all-ceramics with esthetics and biocompatibility were used in the clinical, specially in the anterior. But because of the brittleness of porcelains, these materials could not meet the posterior restorations, to restrict the development of all-ceramics. From the early1990s, zirconia were introduced into dental restorations as the core of the fixed restorations, and the high flexure strength and high fraction toughness were their remarkable advantages, besides good biocompatibility, high stability and esthetics. But because zirconia being consisted by crystals without glass matrix induced bad esthetics and great hardness, the veneering ceramics on the zirconia to simulate the natural teeth and to protect the opposite nature teeth are needed. With the technique CAD/CAM used to making the zirconia cores, bi-layered zirconia restorations had be used in the clinical. However, the clinical statistics showed, the failure rates were higher than the one of metal-ceramics. The mainly failure reasons were:veneering chipping and delamination, secondary caries and so on. In order to solve the problem of chipping and delamination, many investigations in the vitro were taken, from the advancement of material, the analysis of interface, and a finite element analysis of stress. With the increasing of technique, the idea whether the improvement of materials and technique skills or not to rise the bond strength, will become the one of methods to reduce failure rate in these years.Object:In this study, the object is to discuss the effects of the veneering technique on the bond strength and to analyze the difference of interfacial morphology of veneering porcelains with zirconia by the shear bond test and the interfacial micrology observation.Methods:In this study, two technical veneering ceramics were molded on two commercial zirconia surface as the experimental groups, IPS e.max ZirCAD/IPS e.max ZirPress (Group EP), IPS e.max ZirCAD/IPS e.max Ceram (Group EV), Incoris ZI/IPS e.max ZirPress (Group IP), Incoris ZI/IPS e.max Ceram (Group IV) respectively. As the control, two technical dentin ceramics were molded on one nickel-chromium alloy surface, Wiron99/IPS InLine POM (Group NP) and Wiron99/IPS InLine (Group NV). Half of each material groups was thermocycled20000cycles. Subsequently, specimens were subjected to shear force in a universal testing machine. The fracture surfaces and the cross sections were analyzed by the stereomicroscope and FE-SEM (field emission scanning electronic microscope).Results:1.Before thermocycling, the shear bond strengths of Group NP and Group NV were not significantly different from Group EP (P>0.05), and higher than Group EV, Group IP and Group IV (P<0.05), while the values of Group EP were higher than Group IV (P<0.05). After thermocycling, the shear bond strengths of Group NV were higher significantly than Group EP, Group EV, Group IP and Group IV (P<0.05), while the values of Group NP were higer significant than Group EV and Group IV(P<0.05). There are no significant difference among other groups (P>0.05), and between thermocycling and non-thermocycling in the every group (P>0.05). 2. The failure modes were adhesive mainly in the press-on groups, and veneering cohesive mainly in the veneer-on groups on the zirconia surface. On the NiCr surface, the failure modes were comination failure from dentin ceramic to the oxide layer.3. The FE-SEM figure showed that there are more pores and defects in the veneering ceramics and interface in the veneer-on groups than those in the press-on groups in the zirconia system. And the figure of Group NP showed that InLine POM and OP connected closely, and compact in the InLine POM, but a little of pores in the OP layer and the interface of OP and Ni-Cr.4. The energy disperature spectrum of interface displayed the diffusion of element:In the Group EP, from the side of ZirPress to the side of ZirCAD, the element Si was decreased, with the thickness of element transformation about2-3um. In the interface of NiCr and OP, from the side of OP to the side of NiCr, the element of Zr and Si was decreased, with the thickness was about2-3um.Conclusion:1. Compared to the other experimental groups in this study, the bond strengths of ZirCAD and ZirPress were the better to meet the clinical requirement, looking forwards to reduce the clinical failure rate.2. The technique of hot-pressed veneering ceramic was recommended to be used on the surfaces of zirconia and metal core crowns, to reduce the inner defects of veneering ceramics and to improve process efficiency.3. The shear bond strengths of zirconia-veneering ceramics were not affected by two years thermal fatigue treatment.更多还原