漂白处理对人牙本质抗折裂力学行为的影响  

The effect of bleaching on fracture resistance in human dentin

作　　者：徐远志[1] 汪饶饶[1] 安兵兵[2] 周银晓[2] 于海洋[3] 张东升[4] 

机构地区：[1]同济大学附属第十人民医院口腔科 [2]上海市应用数学和力学研究所,上海200072 [3]口腔疾病研究国家重点实验室,四川大学,成都610041 [4]上海大学力学系,上海200444

出　　处：《华西口腔医学杂志》2012年第5期530-534,共5页West China Journal of Stomatology

基　　金：国家自然科学基金资助项目(11172161);上海市自然科学基金资助项目(10zr1423400);上海市科委基金资助项目(104107-01900);上海市教委基金资助项目(12ZZ092);口腔疾病研究国家重点实验室(四川大学)开放基金资助项目(SKLODSCU2009KF03)

摘　　要：目的研究漂白处理对牙本质力学性能的影响。方法采用断裂力学中的内聚力模型并运用有限元分析法,分别模拟牙本质在未漂白、内漂白和外漂白3种状态下的裂纹扩展行为,研究漂白处理对牙本质抗折裂力学行为的影响。结果漂白处理及方式对于牙本质的裂纹扩展阻力都有很大影响,经外漂白处理后的牙本质初始断裂韧度(1.29 MPa.(m)～(1/2))、扩展断裂韧度(3.45 MPa.(m)～(1/2).mm-1)和断裂韧度趋于恒定时的值(2.71 MPa.(m)～(1/2))都比未漂白牙本质的相应值(1.48 MPa.(m)～(1/2)、3.90 MPa.(m)～(1/2).mm-1、3.25 MPa.(m)～(1/2))小,而内漂白处理后的牙本质扩展断裂韧度(0.14 MPa.(m)～(1/2).mm-1)和断裂韧度趋于恒定时的值(1.63 MP.(m)～(1/2))都明显小于外漂白后牙本质的相应值,但是这两种漂白处理后的牙本质初始断裂韧度没有明显差别。结论内聚力模型能很好地预测牙本质的断裂力学行为;漂白处理可以明显降低牙本质的断裂韧度,增加牙齿折裂的风险。Objective To study the effect of bleaching on the mechanical properties of human dentin. Methods The finite element method （FEM） based the cohesive zone model had been employed to study the fracture resistance of human dentin. There types of dentin were considered, i.e. original dentin, dentin after direct-bleaching and indirect- bleaching. Results The bleaching treatments had large impact on the crack growth resistance of human dentin. The initiation toughness （1.48 MPa·√m）, growth toughness （3.90 MPa·√m·mm^-1） and plateau toughness （3.25 MPa·√m ） of human dentin were reduced to 1.29 MPa·√m, 3.45 MPa·√m·mm-1 and 2.71 MPa·√m respectively after indirect- bleaching. The worst case was the direct-bleaching which causes significant reductions in the growth toughness （0.14 MPa·√m·mm^-1） and plateau toughness（1.63 MPa·√m） respectively, while the initiation toughness remained the same as that after indirect-bleaching. Conclusion The cohesive zone modeling is an effective tool in characteri- zing the fracture behavior of human dentin. Bleaching treatments reduce the crack growth resistance of human dentin and increase the risk of fracture of teeth.

关 键 词：牙本质 漂白 断裂韧度 裂纹扩展阻力曲线 

分 类 号：R781.2[医药卫生—口腔医学]