A Comparative Evaluation of the Bond Strength of Universal Resin Luting Cement and Self-adhesive Resin Luting Cement to Zirconia-reinforced Glass Ceramics: An in vitro Study

Abstract

Background: Dental resin cements are widely used for luting indirect restorations, such as ceramic or zirconia crowns, veneers, and inlays, due to their superior mechanical properties and adhesive capabilities. The efficacy of bonding to zirconia and glass ceramics varies by cement type.

Aim: To evaluate and compare the bond strength of universal resin luting cement and self-adhesive resin luting cement, with surface-treated zirconia reinforced glass ceramic.

Materials and methods: Twenty CAD-CAM-milled and fully sintered zirconia-reinforced glass-ceramic (ZGC) blocks of 12 X 14 X 2 mm were prepared. Each specimen was embedded in self-cure acrylic resin cylinders, with one surface exposed for bonding. The specimens were randomly divided into two groups with 10 in each. The specimens in groups 1 and 2 were luted with self-adhesive resin cement and universal resin cement, respectively. The specimens were mounted on the universal testing machine, and the debonding chisel was allowed to make contact with the interface of the luting agent and the ceramic. Then, the load was applied at a crosshead speed of 1mm/min at the interface. The debonding load was recorded in newtons, and the shear bond strength was calculated in MPa. Overall comparisons were analyzed using the Kruskal-Wallis test. Pairwise comparisons were done using the Mann-Whitney U test. The level of significance was set at p < 0.05 for all tests.

Results: Universal resin cement demonstrated a significantly higher mean bond strength (6.94 ± 0.55 MPa) compared to self-adhesive resin cement (5.54 ± 1.09 MPa) with the surface-treated ZGC blocks. Intergroup comparison revealed a statistically significant difference in bond strength between the tested resin cements (p = 0.002).

Conclusion: Universal resin cement demonstrated the highest bond strength, whereas self-adhesive resin cement showed the lowest bond strength to the tested ceramic substrate.