Comparison of the flexural strength of sheets manufactured in three types of zirconium dioxide with two sintering times

Abstract

Introduction: yttrium-stabilized zirconium dioxide (zirconia) has been used to manufacture fixed partial prosthesis due to its high flexural strength. However, there are no available studies comparing the effect of two sintering techniques on flexural strength. This study aims to compare the flexural strength of zirconia sheets manufactured with two sintering techniques. Method: for this in vitro study, three zirconia disks were used (Upcera: Super Translucent (ST): 1200 MPa, Multi-Layer (ML): 600 MPa and High Translucent (HT): 1200 MPa), using an Isomet® cutter to prepare 60 sheets 2 mm thick, 5 mm wide and 37 mm long. These sheets were randomly distributed into two groups of 30: the first group was sintered for 8 hours at 1,530°C and the second group was subjected to fast sintering for 3 hours at 1,530°C. The flexural strength in Newton was measured on an Instrom® 3366 Universal Testing Machine. The results were converted from N to MPa and compared by ANOVA and t test. Results: no statistically significant difference was found in the flexural strength of the two groups (p>0,05). Conclusion: the two compared sintering procedures do not affect the flexural strength of zirconia sheets.

Keywords

• flexural strength
• mechanical properties
• zirconium dioxide
• zro2