代型材料力学性能对磨牙氧化锆全瓷冠断裂失效行为的影响  

Influence of mechanical properties of supporting die materials on fracture strength and failure behaviours of monolithic zirconia molar crowns

作　　者：郭丽娜[1,2] 王晓东 张新平[3] 简裕涛 赵克[1,2] Guo Lina;Wang Xiaodong;Zhang Xinping;Jian Yutao;Zhao Ke(Guanghua School of Stomatology,Hospital of Stomatology,Sun Yat-sen University,Guangdong Provincial Key Laboratory of Stomatology,Guangzhou 510055,China;Guangdong Engineering Research Center of Technology and Materials for Oral Restoration and Reconstruction,Guangzhou 510080,China;School of Materials Science and Engineering,South China University of Technology,Guangzhou 510640,China)

机构地区：[1]中山大学光华口腔医学院.附属口腔医院广东省口腔医学重点实验室,广州510055 [2]广东省牙颌系统修复重建技术与材料工程技术研究中心,广州510080 [3]华南理工大学材料科学与工程学院,广州510640

出　　处：《中华口腔医学研究杂志（电子版）》2019年第1期7-12,共6页Chinese Journal of Stomatological Research(Electronic Edition)

基　　金：国家自然科学基金(81470767;81600907;81771110)~~

摘　　要：目的研究不同力学性能代型材料对磨牙氧化锆全瓷冠断裂失效行为的影响。方法制作弹性模量与牙本质(18.6 GPa)近似的复合树脂和多孔钛标准试件(n=40),测定其维氏硬度、挠曲强度和断裂韧性值。分别用离体牙及上述复合树脂和多孔钛制作代型(n=10),制作30个单层瓷结构的全锆(M-Zir)冠,采用随机数字表法分为3组,分别粘接于离体牙预备体及多孔钛和复合树脂代型上。所有试件行抗折破坏试验,记录最大断裂载荷(N)及失效模式,并采用扫描电镜行断口形貌学分析。使用SPSS 20.0软件对代型材料的力学性能测定结果进行独立样本t检验,抗折破坏试验进行单因素方差分析和LSD-t检验。结果多孔钛与P60复合树脂的弹性模量分别为(18.50±1.65)和(17.48±1.70)GPa,两组间差异无统计学意义(t=1.358,P=0.191)。多孔钛材料的维氏硬度(165.60±11.17)HV、挠曲强度(522.47±52.46)MPa和断裂韧性(3.67±1.18)MPa·m^(1/2)显著高于复合树脂(P<0.001)。离体牙组、多孔钛代型组、复合树脂代型组M-Zir冠的平均断裂载荷分别为(5 306±467)、(5 273±447)和(4 695±583)N,3组差异有统计学意义(F=4.253,P=0.025)。多孔钛代型组与离体牙组差异无统计学意义(P=0.890),复合树脂代型组显著低于离体牙组(P=0.015)及多孔钛代型组(P=0.021)。全瓷冠断裂模式分析显示,3组的M-Zir冠断裂模式无明显差异,均为瓷全层折裂为颊颚侧2块,裂纹通过中央窝沟向近远中牙尖三角嵴方向扩展。同时,离体牙组试件多伴有预备体的损伤,复合树脂代型组全部试件均伴有代型折裂,多孔钛代型组全部试件均完整。结论多孔钛的维氏硬度、挠曲强度及断裂韧性优于复合树脂材料。使用复合树脂材料作为代型时M-Zir冠断裂载荷偏低,但对其断裂模式无明显影响。多孔钛代型较复合树脂代型更适用于高强度氧化锆全瓷修复体的体外研究。Objective The aim of this study was to investigate the influence of supporting die with various mechanical properties on the fracture strength and failure mode of monolithic zirconia crowns.Methods Standard composite resin and porous titanium specimens(n=40)with elastic modulus similar to human dentin(18.6 GPa)were fabricated.Mechanical properties,including Vicker′s hardness,flexural strength and fracture toughness were evaluated.Extracted teeth(n=10)were prepared into resin(n=10).Subsequently,30 monolithic zirconia(M-Zir)single crowns were milled and cemented onto the above three types of substrates.Load-to-failure test was conducted for all samples with universal testing machine,from which fracture strength was recorded,followed by the failure mode.Fractographic analysis was done by using scanning electron microscopy.Mechanical Properties Tests of die materials were statistically analyzed with t test,whereas Load-to-failure test was done with One-way ANOVA and LSD-t test(SPSS 20.0).Results The elastic modulus of porous titanium and composite resin was(18.50±1.65)and(17.48±1.70)GPa,respectively.There was no statistical difference between the two groups(t=1.358,P=0.191).The Vicker′s hardness(165.60±11.17)HV,flexural strength(522.47±52.46)MPa and fracture toughness(3.67±1.18)MPa·m^1/2 of porous titanium were noted significantly higher than those of composite resin(P<0.001).The average fracture strength of monolithic zirconia crowns cemented on the dentin,porous titanium and composite resin dies was(5 306±467),(5 273±447)and(4 695±583)N,respectively.No significant difference was found among the three groups(F=4.253,P=0.025).The average fracture strength of the composite resin substrates was significantly lower than that on dentin(P=0.015)and porous titanium(P=0.021),while no difference was found between the dentin and porous titanium group(P=0.890).Similar fracture mode of the M-Zir crowns that built on the three different substrates was noticed.All crowns broke into two pieces with cracks extending ob

关 键 词：挠曲强度 代型材料 力学性能 氧化锆 断口形貌分析 

分 类 号：R783.1[医药卫生—口腔医学]