Effect of Shading on Flexural Strength of Zirkonzahn; Zirconia-Based Ceramics

Abstract

Introduction: Despite high strength of pure Zirconia, it is too white to achieve all esthetic treatment needs in some patients. It seems that adding color agent affects the mechanical properties of Zirconia and its fracture strength. The objective of the current study was to compare the fracture strength of Zirkonzahn ceramics using colors A3, B3, D3 and the one without coloring.Materials & Methods: In the current study, disc-shaped Zirkonzahn specimens were fabricated using standard principles with the dimensions of 1×15 mm and randomly colored using A3, B3 and D3 shades (10 specimens for each group). Furthermore, 10 uncolored specimens were also considered as control group. The fracture strength of the specimens was measured using biaxial flexural strength method and piston-on-3-balls test. The elements in the specimens were determined by EDX (Energy Dispersive XRay) examinations. The data relevant to flexural strength were subjected to one-way ANOVA test.Results: Flexural strength of uncolored Zirkonzahn specimens was 1449.61 MPa. These values were found to be 1660.72MPa, 1624.28 MPa and 1496.38 MPa in the specimens colored by A3, B3 and D3 shades respectively. No significant differences were found among different groups regarding the mean of fracture strength. Conclusion: It seems that flexural strength of Zirkonzahn was not influenced by coloring factor or the kind of colors used.

Keywords

• Flexural strength
• zirconia
• color shade