Cyclic fatigue behaviour of hydrothermally aged 3Y-TZP ceramics in 4-point bending tests

Fatigue is one of the most important properties to be considered in ceramic dental implants due cyclic mechanical stresses arising from chewing process. In this work, fatigue behaviour hydrothermally degraded ZrO2-based ceramics stabilized with 3mol% Y2O3 (3Y-TZP) was studied 4-point bending tests. Samples 3Y-TZP were compacted (100MPa), sintered at 1475 ?C for 2 h, polished and an autoclave as described ISO-13356 standard. The samples characterized by their relative density, crystalline phase composition, microstructure surface roughness. highly dense (>99.6%TD) has only tetragonal t-ZrO2 phase, even after hydrothermal ageing. Furthermore, materials presented a Vickers hardness 12.7?0.2GPa, fracture toughness 7.1?0.3MPa?m1/2 strength 940.1?67MPa. Based on test results 5 different stress levels tests selected conducted obtaining S-N curve. Weibull statistics used statistical analysis. indicate that limit resistance around 550MPa, i.e. higher than limits established standard use Y-TZP manufacture implants. investigated related toughening mechanisms acting ceramics, such transformation t?m microcracking.