Abstract

DULLABH, H; HERBST, D; SYKES, L  and  BISESWAR, N. Biaxial flexural strength of three ceramic oxide core materials. S. Afr. dent. j. [online]. 2017, vol.72, n.2, pp.56-61. ISSN 0375-1562.

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: 1. To compare the biaxial flexural strengths 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 CONCLUSIONS: 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.

Keywords : High-strength ceramics; tensile stress.

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