Edition V16N01 | Year 2011 | Editorial Article | Pages 37 to 47
Objective: To evaluate the influence of the surface treatment of acrylic resins on the shear bond strength of brackets bonded with composite resin. Material and Methods: Were fabricated 140 discs with autopolymerizing acrylic resin (Duralay®) and divided them into 14 groups (n = 10). In each group, the specimens received a different type of surface treatment. Group 1- untreated surface (control), Group 2- silane, Group 3- aluminum oxide blasting (AOB), Group 4- AOB + silane, Group 5- diamond bur, Group 6- diamond bur + silane, Group 7- hydrofluoric acid, Group 8- hydrofluoric acid + silane, Group 9- phosphoric acid, Group 10- phosphoric acid + silane, Group 11-methylmethacrylate monomer (MMA), Group 12- MMA + silane, Group 13- plastic conditioner (Reliance®); Group 14- plastic conditioner (Reliance®) + silane. After surface treatment the specimens were analyzed using a surface roughness tester. Subsequently, standard edgewise central incisor brackets (Morelli®) were bonded using Transbond XT® light-cure adhesive system, according to the manufacturer?s instructions. Results: The silane-based wetting agent had no statistically significant effect on bond strength values. Treatments with AOB and bur generated the highest topographical changes on the surface of acrylic resin as well as the highest roughness values. A nonlinear correlation was found between bond strength and surface roughness. Monomer + AOB treatment yielded the highest bond strength values. Conclusions: Silane failed to increase the bond strength between brackets and acrylic resin. We encourage further studies on this subject since the bond strength achieved in our study was extremely low.