Technical note: Resin-to-metal bonds mediated by adhesion promoters

This study aimed to establish whether the bonding between a composite cement (Comspan Opaque) and grit-blasted nickel-chromium alloy (Biobond Plus) could be enhanced by pre-treatment of the alloy surface with adhesion promoters. Six groups of metal adherends, of ten specimens each, were prepared. The specimens in each group were finished flat and blasted with 50 μm alumina. The first group was used without further treatment of the metal surface. A second group was electrolytically etched. Each of the remaining four groups was treated with an adhesion promoter. The resin cement was bonded to the adherend and, after 24 h in water at 37°C, the tensile bond strengths were determined. ANOVA and the Scheffé test at the 0.05 level showed that Scotchbond dual-cure dental adhesive enhanced the resin-to-metal bond significantly and produced a mean bond strength value (30.9 MPa) higher than that obtained with electrolytic etching (22.7 MPa) or grit-blasting (14.6 MPa). This would appear to be of considerable significance. The metal primers, ABC primer and GoldLink, and the ceramic primer, Scotchprime, were much less effective than Scotchbond dual-cure.