Patients in orthodontic treatments frequently present composite restorations. However, few studies evaluated the influence of bonding materials within braces shearing bond strength on composite surfaces. The acrylic resin became the recommended material for bonding brackets on these surfaces; however the use of cyanoacrylate emerged as a potential option. The present study aimed to evaluate the performance of cyanoacrylate associated with orthodontic materials commonly used for the fixation of metallic braces on temporary restorations of acrylic resin. Forty samples were prepared with acrylic resin and homogenized with silicon carbide sand paper (320 and 600). The samples were randomly divided in four groups (n=10) based on the material treatment and bonding agent: G1 - braces bonded with acrylic resin; G2 - braces bonded with acrylic resin combined with application of cyanoacrylate; G3 - braces bonded with Transbond(tm) XT; G4 - braces bonded with Transbond(tm) XT combined with application of cyanoacrylate. Only stainless steel braces were used, prescription Roth, Kirium (3M/Abzil) designed for maxillary right central incisors, slot 022. After bonding, the sample underwent shearing tests at 0.5mm/min within a standard testing device (EMIC DL-1000). Statistical data consisted of ANOVA with significance level set at 5%. Group 2 (G2) reached major shearing strength (13.76 MPa). However, it was not statistically significant in face of the outcomes of Group 1 (G1) (G1= 7.76 MPa). The same was observed for the association of Transbond(tm) XT and cyanoacrylate (G4= 4.03MPa) compared with isolated Transbond(tm) XT (G3= 3.87 MPa) and acrylic resin. Surface treatment of orthodontic material revealed a significant effect on shearing strength of temporary materials. The association between cyanoacrylate with monomer of methyl methacrylate presented major shearing strength, becoming more indicated for clinical interventions.
Orthodontics; Shear Bond Strength; Dental Bonding; Composite Resin; Acrylic resin
