Surface modification with alumina blasting and H2SO4–HCl etching for bonding two resin‐composite veneers to titanium

The purpose of this study was to investigate the effect of an experimental surface treatment with alumina blasting and acid etching on the bond strengths between each of two resin composites and commercially pure titanium. The titanium surface was blasted with alumina and then etched with 45wt% H₂SO₄ and 15wt% HCl (H₂SO₄–HCl). A light‐ and heat‐curing resin composite (Estenia) and a light‐curing resin composite (Ceramage) were used with adjunctive metal primers. Veneered specimens were subjected to thermal cycling between 4 and 60°C for 50,000 cycles, and the shear bond strengths were determined. The highest bond strengths were obtained for Blasting/H₂SO₄‐HCl/Estenia (30.2 ± 4.5 MPa) and Blasting/Etching/Ceramage (26.0 ± 4.5 MPa), the values of which were not statistically different, followed by Blasting/No etching/Estenia (20.4 ± 2.4 MPa) and Blasting/No etching/Ceramage (0.8 ± 0.3 MPa). Scanning electron microscopy observations revealed that alumina blasting and H₂SO₄–HCl etching creates a number of micro‐ and nanoscale cavities on the titanium surface, which contribute to adhesive bonding.