Impact of resin cement viscosity on bond strength to different zirconia ceramics after aging condition

Abstract

Objective: The current study examined how varying resin cement viscosities (high and low) impact the microshear bond strength (μSBS) of two distinct zirconia ceramics – 3Y-TZP and 4Y-PSZ– following an aging process. Material and Methods: Square zirconia samples were prepared and encased in PVC cylinders using acrylic resin, then sorted into four groups according to the resin cement viscosity (high or low) and zirconia type (3Y-TZP or 4Y-PSZ) factors. The ceramic surfaces were treated with air abrasion using 45 μm aluminum oxide particles, followed by the application of an MDP-containing primer agent. Starch tubes were filled with resin cement of differing viscosities. Subsequently, the resin cement cylinders (n = 20) underwent an aging process, which involved 12,000 cycles of thermocycling and storage for 120 days, followed by microshear bond strength testing. Statistical analysis was performed using two-way ANOVA and Tukey’s post-hoc tests. Results: Neither the resin cement (p = 0.42) nor the type of ceramic (p = 0.97) significantly influenced the bond strength. Scanning electron microscopy analysis demonstrated similar surface topography for both ceramics after air abrasion. This resemblance was further confirmed by atomic force microscopy (AFM), showing similarities in topography and fractal dimension between the ceramics. Moreover, the predominant failure mode observed was adhesive. Conclusion: Within the present context, resin cement viscosity does not adversely affect the achievement of satisfactory bond strength values in the evaluated zirconia ceramics.

KEYWORDS

Aging; Composite resin; Ceramics; Dental adhesives; Shear strength.