Abstract:
INTRODUCTION :
Brittleness and low strength render conventional ceramic
systems unsuitable for routine restorative use in molars.
Modern, high-strength ceramic core materials such as
high purity aluminum oxide (Al2O3) and yttrium - partially
stabilized zirconia (Y-PSZ) have been designed for
aesthetic, metal-free, all-ceramics in posterior teeth.
AIMS AND OBJECTIVES :
To compare the biaxial flexural strengths 1. of these two
core materials.
2. To compare the strengths of Y-PSZ samples produced
by two manufacturers.
MATERIALS AND METHODS :
Three groups of discs measuring 16mm diameter and
2mm thickness were prepared for each of the sample
materials, high purity Al2O3, commercially available as
Turkom-Cera, and Y-PSZ, commercially available as
Cercon and LAVA. The Biaxial flexural strengths were
measured using a Zwick Z010 Material Testing Machine.
Reliability was compared using Weibull Moduli.
RESULTS :
Mean strengths for LAVA, Cercon and Turkom-Cera were
866.44, 586.92, 155.71 MPa respectively. Statistically significant
differences were shown between the mean values.
DISCUSSION AND CONCLUSION :
This project showed that the samples of Y-PSZ had higher
biaxial flexural strengths than those of high purity Al2O3. The
biaxial flexural strengths of Y-PSZ, sourced from two manufacturers,
are significantly different. It is suggested that Y-PSZ
is suitable and indicated for restorative use in molar regions.
