Orthodontic bonding to high-copper amalgam with different adhesive cements

Abstract

Objective: The aim of this study was to compare the shear bond strengths of metal brackets bonded by four different adhesive cements to high-copper amalgam surfaces. Materials and Methods: A commonly used dental amalgam (nongamma 2, lathe-cut, high-copper alloy) (Cavex Avalloy, Cavex) was triturated according to the manufacturers′ directions, and then condensed into a cylindrical (diameter: 8 mm, depth: 2 mm) undercut cavity prepared in auto polymerized acrylic resin. Exposed surfaces of 100 specimens were polished with 400, 600, 800, and 1200 grit paper and cleaned for 10 min under running tap water, air-dried, sandblasted for 3 s with 50-micron aluminum oxide abrasive, and coated with alloy primer (Alloy PrimerTM, Kuraray). Lower incisors metal brackets were bonded to prepared surfaces with an orthodontic composite Transbond XT (3M) (control) and four adhesive cements: C and B Metabond (Parkell), Panavia F 2.0 (Kuraray), Resinomer (Bisco), and Bis Cem (Bisco). After 24 h, all samples were tested for shear bond strength with the universal test machine. The data were calculated as MPa and statistically analyzed. Results: Statistically bond strengths of Panavia F 2.0 and C and B Metabond were higher than the bond strengths of Bis Cem and Resinomer (P < 0.05). There was no difference between the bond strength of control group (Transbond XT) and the other adhesive cements tested (P > 0.05). Conclusion: Bonding the brackets to sand blasted and alloy primer coated amalgam surfaces can be achieved by traditional orthodontic composites (Transbond XT). Panavia F 2.0 and C and B Metabond adhesive cements may improve bonding to high-copper amalgam.