Orthodontic Bonding to High Copper Amalgam with Different Adhesive Cements

METHODS: A commonly used dental amalgam (non-gamma 2, lathe-cut, high-copper alloy) (Cavex Avalloy, Cavex Netherlands) was triturated according to the manufacturer's recommendations and then condensed into a cylindrical (diameter: 8 mm, depth: 2 mm) undercut cavity prepared in autopolymerized acrylic resin (Meliodent, Heraeus Kulzer, Germany). Exposed surfaces of 100 specimens was polished with, 400, 600, 800 and finally 1200 grit paper (Struers RotoPol 11, Struers A/S, Denmark) and cleaned for 10 minutes under running tap water, air-dried, sandblasted for 3 seconds with 50 micron aluminum oxide abrasive and coated with alloy primer (Alloy Primer, Kuraray, Japan). Lower incisors metal brackets were bonded to prepared surfaces with an orthodontic composite Transbond XT (3M) (Control) and four adhesive cements: C&B Metabond (Parkell, USA), Panavia F 2.0 (Kuraray, Japan), Resinomer (Bisco, Canada), Bis Cem (Bisco, Canada). After 24 hour all samples were tested for shear bond strength with the universal test machine. The data were statistically analyzed.

RESULTS: Statistically bond strengths of Panavia F 2.0 (52,7±20,5) and C&B Metabond (52,7±19) was higher than the bond strengths of Bis Cem (19,9±18,5) and Resinomer (18,9±16,1) (p<0.05). There were no difference between the bond strength of control group (Transbond XT) (33,9±16,37) and the other adhesive cements tested (p>0.05).

CONCLUSION: Bonding the brackets to sandblasted and alloy primer coated amalgam surfaces can be achieved by traditional orthodontic composites (Transbond XT). Panavia F 2.0 and C&B Metabond adhesive cements may improve bonding to amalgam.