Effect of Self-Adhesive Resin Cement on Bond Strength to Restorative Metal Materials

Abstract

Purpose: To evaluate the shear bond strength of six self-adhesive resin cements to five restorative metal materials.
Methods: Five restorative metal materials blocks were obtained by casting and polishing with #600 silicon carbide papers: (1) titanium, (2) nickel-chromium alloy, (3) gold alloy type 3, (4) silver-palladium-copper-gold alloy, (5) metal-ceramic gold alloy. The following six self-adhesive resin cements: Maxcem (MA), Unicem (UN), Breeze (BR), Biscem (BI), Set (SE), Clearfil SA luting (CL) and one conventional resin cement: Resicem (RE) were used to bond to five restorative metal materials in this study. Prior to testing specimens were stored in distilled water (37°C) for 24 h. The bond strength tests were performed in a universal testing machine (cross-head speed: 0.5 mm/min). Data were analyzed using Kruskal-Wallis test and the Wilcoxon rank sum test for multiple pairwise comparisons. Failure modes were recorded and the interfacial morphologies of debonded specimens were observed by scanning electron microscope (SEM).
Results: The mean values of shear bond strength were 2.6 ± 1.9 MPa for gold alloy type 3, 2.2 ± 1.7 MPa for silver-palladium-copper-gold alloy, 5.0 ± 2.3 MPa for metal-ceramic gold alloy, 10.2 ± 5.4 MPa for titanium, and 9.9 ± 7.8 MPa for nickel-chromium alloy.
Conclusion: Self-adhesive resin cement is not suitable to bond noble metal without surface treatment. The shear bond strengths of BR, BI, and CL to non-precious metals were significantly higher than other resin cements.