Evaluation of Shear Bond Strength of Zirconia to Resin Cement After Surface Treatment with Different Air Abrasion Zirconia Particles

Abstract

The aim of the study: This in vitro study aims to assess the shear bond strength of different zirconia generations 3Y-TZP, 4Y-PSZ, and 5Y-PSZ and resin cement after surface modification using different abrasive particles, zirconia (beads and sharp edge particles) and aluminum oxide sharp edge in comparison to control (no surface treatment). Material and methods: Ninety zirconia discs (W 19.42x H 2.04), comprising 30 each of 3% Y-TZP, 4% Y-PSZ, and 5% Y-PSZ, were provided by Dentium ( Rainbow™). The specimens were lapped and polished with 6-micron diamond slurry and 3-micron diamond slurry, respectively. Surface treatments included 50-micron aluminum oxide abrasive particles, 50-micron zirconia abrasive bead particles, 50-micron zirconia abrasive sharp edges particles, and a control group (no surface treatment). After surface treatment, bonding was conducted using SpeedCEM Plus self-adhesive dual cure resin cement (Ivoclar Vivadent Inc.), and shear bond strength was assessed by a universal testing machine ( Instron LLC.), following ISO standards (ISO 29022). Failure analysis was performed to classify failure types. Statistical analyses were conducted to evaluate the data. A one-way ANOVA, followed by Dunnett's multiple comparisons test, assessed differences in shear bond strength between the control group and various zirconia generation and different surface treatment groups. Furthermore, a Two-way ANOVA, followed by Tukey's multiple comparisons test, examined effect of different surface treatment and material generation to the shear bond strength. Statistical significance was set at α = 0.05 for all analyses. Result: A significant increase in shear bond strength in all surface treatment groups compared to control. Aluminum oxide abrasive particle surface treatment groups demonstrated significantly higher bond strengths compared to zirconia abrasive particle surface treatment groups. There was no statistically significant improvement in the bond strength with different geometry of zirconia abrasive particles. Additionally, zirconia generation influenced bond strength, with higher values vi observed in 5Y-PSZ compared to 4Y-PSZ in the zirconia abrasive particles surface treatment group. However, there was no statistically significant Aluminum oxide abrasive particle regardless of zirconia generation. Failure analysis revealed aluminum oxide abrasives groups demonstrated 50% adhesive failure and 50% mixed failure. The zirconia abrasive bead particle groups had 63.3% adhesive failure and 38.3% mixed failure. The group that received the zirconia abrasive sharp edges particles groups 53.3% adhesive failure and 46.6% mixed failure. SEM confirms residual particles on zirconia surfaces treated with zirconia abrasives and significant roughness with aluminum oxide abrasives. Conclusion: Micromechanical surface treatment with aluminum oxide abrasive particles significantly improves bond strength compared to zirconia abrasive particles. Furthermore, regardless of the shape of zirconia abrasive particles, there was no statistically significant improvement in bond strength. Notably, all zirconia generations responded similarly to surface treatment with aluminum oxide abrasive particles; however, 4Y-PSZ exhibits weakened bond strength with zirconia abrasive particles.