Comparative Flexural strength of two types of monolithic zirconium oxide long-span fixed partial dentures

Objectives:The purpose of this study was to evaluate the flexural strength of two types of monolithic zirconium oxide long-span fixed partial dentures (FPDs).The monolithic materials used in the study were (InCoris TZI C and Bruxzir shaded 16).Readily prepared ivory teeth were used to simulate a 4-unit FPD with 22 mm span length.A total number of 40 FPDs 4 units FBDs were distributed into two main groups based on the construction material type, each counting 20 FPDs.Twenty FPDs were fabricated using InCoris TZI C (group 1) and the other twenty FBDs were fabricated using Bruxzir shaded 16 (group 2).FPDs were manufactured according to CAD/CAM technique.All specimens were stored in water for 24 hours and then subjected to 10,000 thermal cycles then mechanically loaded for 10.000 preloading cycles at loads between minimum 10 N and maximum 89N at 1HZ frequency.and then loaded until failure in a universal testing machine.The 3-point bending test was done to evaluate the flexural strength of the FPDs using Instron testing machine.Results.Bruxzir shaded 16 has recorded the highest mean of values at a level of (928.55Mpa± 66.13), while those recorded for InCoris TZI C group of specimens were at the level of (845.21Mpa±83.54).T-test revealed a highly statistical significant difference between both tested monolithic zirconia materials at the value level of P<0.001.