Does the Duration of Acid Treatment Affect the Bond Strength Between Resin Cement and Zirconia

Abstract

Statement of the problem: The bonding between the resin cement and zirconia still needs to be improved and the effect of the experimental acid application duration on the resin bond strength with zirconia is unk-nown. Objective: This study aimed to investigate the effect of different acid application times on the shear bond strength between zirconia and dual-cure resin cement. Materials & Methods: A total of 50 zirconia disks were prepared in 2 mm thickness and randomly divided into five treatment groups: control (no treatment was applied), 30 seconds HF:H2O:H2O2 acid application group, 60 seconds HF:H2O:H2O2 acid application group, 90 seconds HF:H2O:H2O2 acid application group, and 120 seconds HF:H2O:H2O2 acid application group. Then a dual-cure resin cement was applied over the 3 mm diameter and 3 mm thickness of the zirconia specimens. The speci-mens were immersed in distilled water and maintained at a temperature of 37°C for a duration of 24 hours. The shear bond strength tests were perfor-med using a universal testing machine with a force of 1 mm/min until the fracture occurs, and the data were analyzed using one-way ANOVA and Tukey's post-hoc test. Results: The highest mean shear bond strength was found in the 90 seconds acid application group, which was significantly higher than the control and 30 seconds acid application groups (P<0.05). However, the 60- and 120 seconds acid application groups showed similar shear bond strength values with the control, 30- and 90 seconds acid application groups (P>0.05). Conclusions: The use of a 60-, 90- and 120 seconds acid application can improve the bond strength between zirconia and resin cement. However, caution should be taken when using this acid due to its potential toxicity and hazards.