title: Strength degradation and lifetime prediction of dental zirconia ceramics under cyclic normal loading.
abstract: Clinical cases show that zirconia restoration could happen fracture by accident under overloading after using a period of time. The purpose of this study is to research mechanical behavior and predict lifetime of dental zirconia ceramics under cyclic normal contact loading with experiments. Cyclic normal contact loading test and three point bending test are carried on specimens made of two brands of dental zirconia ceramic to obtain flexure strength and damage degree after different number of loading cycles. By means of damage mechanics model, damage degree under different number of contact loading cycles are calculated according to flexure strength, and verified by SEM photographs of cross section morphology of zirconia ceramics specimen phenomenologically. Relation curve of damage degree and number of cycles is fitted by polynomial fitting, then the number of loading cycles can be concluded when the specimen is complete damage. Strength degradation of two brands dental zirconia ceramics are researched in vitro, and prediction method of contact fatigue lifetime is established.
authors.affiliation: School of Mechanical Engineering, Northwestern Polytechnical University, Xi'an, Shaanxi, P.R. China.
authors.forename: Wanzhong
authors.initials: W
authors.lastname: Li
authors.affiliation: School of Mechanical Engineering, Northwestern Polytechnical University, Xi'an, Shaanxi, P.R. China.
authors.forename: Yingqiang
authors.initials: Y
authors.lastname: Xu
authors.affiliation: School of Stomatology, The Fourth Military Medical University, Xi'an, Shaanxi, P.R. China.
authors.forename: Huiming
authors.initials: H
authors.lastname: He
authors.affiliation: The 309th Hospital of Chinese People's Liberation Army, Beijing, P.R. China.
authors.forename: Haidan
authors.initials: H
authors.lastname: Zhao
authors.affiliation: School of Mechanical Engineering, Northwestern Polytechnical University, Xi'an, Shaanxi, P.R. China.
authors.forename: Jian
authors.initials: J
authors.lastname: Sun
authors.affiliation: School of Mechanical Engineering, Northwestern Polytechnical University, Xi'an, Shaanxi, P.R. China.
authors.forename: Yue
authors.initials: Y
authors.lastname: Hou
mesh_terms: D040761:Biomimetic Materials / Q000737:chemistry*; D001732:Bite Force; D002516:Ceramics / Q000737:chemistry*; D003764:Dental Materials / Q000737:chemistry*; D019554:Dental Restoration Wear; D003799:Dental Stress Analysis; D055119:Elastic Modulus; D006244:Hardness; D008422:Materials Testing; D013314:Stress, Mechanical; D013718:Tensile Strength; D013997:Time Factors; D015040:Zirconium / Q000737:chemistry*
chemical_list: D003764:Dental Materials; D015040:Zirconium; C028541:zirconium oxide
keywords: Strength degradation; damage degree; flexure strength; lifetime prediction; normal cyclic load