Influence Of Dynamic Cyclic Loading On The Bi-Axial Flexural Strength Of Veneering Porcelain For Zirconia Under Simulated Saliva Immersion And Dry Conditions

Objective The purpose of this study was to determine the influence of dynamic cyclic loading on the bi-axial flexural strength of veneering porcelain for zirconia under simulated saliva immersion and dry conditions.Methods Standardized disc specimens(30) were randomly divided and stored into tow group (simulated saliva immersion (pH 7) and dry conditions), than taken to proceed biaxial flexural strength test. Optical microscopy was employed for identification of the fracture mode and origin.Results Flexural strength of specimens that are tested under dry conditions are approximately 70% stronger than those in wet environment.Conclusion the fatigue appearance in dental Zirconia ceramic Material is related to the immersion of dental ceramic prosthesis in humidite conditions(saliva). Objectives to determine the influence of cyclic loading test under different storage mediums condition on the bi-axial flexural strength of veneering porcelain for zirconia.Methods Standardized disc specimens (16 mm×1.6 mm) were pre-loaded 10,000 cycles and stored in pH 2 or pH 12 environment prior to biaxial flexural strength (ISO 6872 standard). A Weibull statistical approach was also utilized in order to describe the reliability of the failure strength data.Results Flexural strength of specimens that were tested under dry conditions were approximately 20~50% stronger than those in wet environment; flexural strength of specimens in acid solutions were approximately 30% stronger than those were soaked in alkaline solutions.Conclusion The test result is help to guide the clinical application of all-ceramics dental crown, which is obtained with bi-axial flexural strength at different storage mediums.