This study aimed to compare the shear bond strengths of metal brackets bonded to amalgam surfaces.
One hundred and fifty amalgam samples were fabricated and either polished, roughened with a diamond bur or sandblasted with 50 mm aluminium oxide. Following thermocycling the shear bond strengths were tested and compared with control samples bonded to etched enamel.
Concise resin composite, Metal Primer/Concise resin composite and All-Bond II/Concise resin composite bonded to sandblasted amalgam gave the highest mean shear strengths and were statistically similar to the etched enamel/Concise resin composite controls.
One would expect sandblasted amalgam surfaces to be associated with higher shear bond strengths than diamond bur roughened or polished amalgam surfaces.