Flexural strength of  two Y-TZP porcelains with various firing temperatures

Evaluate the flexural strength of two Y-TZP conventional veneering porcelains  and the effect of modifying their peak  firing temperatures.

Method:

- Two materials : Cercon^® ceram love , Cercon^® ceram kiss (DeguDent, Germany).

- A silicon mold was used with dimensions of 27x3x4 mm to make bar shaped specimens. Powder slurry mix was vibrated and condensed into the mold. Sixty bars were fabricated and randomly divided into six groups. Two groups were fired according to the manufacturer's recommendation. The peak firing temperature were modified to be ±10C^o for the remaining groups. All specimens were tested with Three-point bend test using a universal testing machine (Instron) with crosshead speed of 0.5 mm/min.

Result:

Flexural strength data for veneering porcelains were: 

LOVE : (815 C^o), 51.1±16.56MPa; (825 C^o), 59.33±9.9MPa; (835 C^o), 65.7±10.46MPa

KISS : (815 C^o), 75.94±2.85 MPa; (825 C^o), 59.6±7.82 MPa; (835 C^o), 75.28±5.63MPa

Conclusion:

There is no significant difference in the flexural strength between the two veneering porcelains. Modifying the firing temperature for Cercon^® ceram love has no significant effect on its flexural strength, While it has significant effect on the flexural strength of  Cercon^® ceram kiss.