Strength degradation and lifetime prediction of dental zirconia ceramics under cyclic normal loading

Abstract

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.

The study of aging, fatigue and degradation for the purpose of improving the reliability of dental Zirconia ceramics. A review of articles in world`s journals

“…Для подтверждения расчетов они провели испытания образцов на прочность при изгибе и исследования морфологии поперечного среза материала на сканирующем электронном микроскопе. Авторы утверждают, что разработанный ими метод позволит прогнозировать срок клинической службы цирконовой реставрации до наступления контактного усталостного разрушения материала [31].…”