Shear bond strength of orthodontic brackets to enamel under different surface treatment conditions

Abstract

The purpose of the present study was to evaluate the shear bond strength to enamel and the adhesive remnant index (ARI) of both metallic and polycarbonate brackets bonded under different conditions. Ninety bovine permanent mandibular incisors were embedded in acrylic resin using PVC rings as molds and assigned to 6 groups (n=15). In Groups 1 (control) and 3, metallic and polycarbonate orthodontic brackets were, respectively, bonded to the enamel surfaces using Transbond XT composite according to the manufacturer's recommendations. In Groups 2 and 4, both types of brackets were bonded to enamel with Transbond XT composite, but XT primer was replaced by the OrthoPrimer agent. In Groups 5 and 6, the polycarbonate bracket bases were sandblasted with 50-μm aluminum-oxide particle stream and bonded to the enamel surfaces prepared under the same conditions described in Groups 3 and 4, respectively. After bonding, the specimens were stored in distilled water at 37°C for 24 hours and then submitted to shear bond strength test at a crosshead speed of 0.5 mm/min. The results (MPa) showed no statistically significant difference between Groups 4 and 6 (p>0.05). Likewise, no statistically significant differences (p>0.05) were found among Groups 1, 2, and 5, although their results were significantly lower than those of Groups 4 and 6 (p<0.05). Group 3 had statistically significant lower bond strength than Groups 2, 4, and 6, but no statistically significant differences were found on comparison to Groups 1 and 5. A larger number of fractures at the bracket/composite interface were evidenced by the ARI scores. OrthoPrimer bonding agent yielded higher bond strength in the groups using either conventional or sandblasted polycarbonate brackets, which was not observed in the groups using metallic brackets.

Novel antibacterial orthodontic cement containing quaternary ammonium monomer dimethylaminododecyl methacrylate

“…In the present study, the shear bond strengths ranged from 13.1 to 14.6 MPa. Other previous studies using commercial orthodontic adhesive reported similar shear bond strengths values (Pithon et al 2007; Akhavan et al 2013). Hence, the new antibacterial DMADDM-containing orthodontic bracket cement of the present study with 3% DMADDM appeared to yield an adequate orthodontic bond strength to enamel.…”

Qualitative Evaluation of the Bracket-Adhesive-Enamel Junction of Metal Orthodontic Brackets: A Preliminary Report

“…Some of the features of ideal orthodontic adhesives are: sufficient working time for the dentist, fluoride release, good bonding, and easy removal without damaging the enamel surface, with minimal polishing needed (1)(2)(3). Another ideal feature that has not been tested before is the easy removal of the adhesive from the areas around the enamel and orthodontic bracket, after bonding and before setting, anticipating a smooth surface.…”

Influence of Primekote® polymer in orthodontic bonding

“…One of the main goals of current orthodontic research is to obtain materials for bracket bonding that provides proper adhesion strength between resin, bracket and tooth in order to withstand masticatory loads and orthodontic forces and to resist the presence of fluids of the oral cavity and the interference of such fluids 6,7 . Fracture lines in bracket displacement in vivo and in vitro usually occur in the bracket/adhesive interface.…”