INFLUENCE OF DIFFERENT AIR ABRASION PRESSURE ON SHEAR BOND STRENGTH OF DIFFERENT TYPES OF ZIRCONIA

Abstract

This study aimed to evaluate the use of different pressure of air particle abrasion (APA) on four different types of monolithic zirconia and its effect on their shear bond strength. Methodology: The study was divided into 4 groups according to the type of monolithic zirconia used: opaque, high translucency, ultra-high translucency and supra-high translucency. Each group was subdivided into two groups according to the amount of APA application used (2 or 4 bars). For the treatment of the zirconia specimens, zirconia MDP containing primer was applied on the cemented surface. Composite resin cubes were fabricated and cemented over zirconia cubes under 5kg for 6 minutes.Shear bond strength test was carried out on an Instron machine at a speed of 0.5mm/min, with the load measured in Newtons and the SBS determined as follows: Load (N)/area = SBS. Effect of APA application were examined using scanning electron microscopy to determine surface roughness on different tested zirconia groups. The data was statistically analized. Results: The one way ANOVA test revealed statistical differences between the APA pressure groups (P<0.001). Statistical analysis showed that high translucent zirconia scored the highest shear bond after using 2 bar and 4 bar APA in comparison to all other groups; the shear bond strength increased with increasing the pressure. Conclusion: The lower values of shear bond strength in successive, more translucent generations, forewarning the necessity for greater caution in clinical implementation.