Effect of Activation Mode on Shear Bond Strength of Metallic Brackets

Américo Bortolazzo Correr, Ana Rosa Costa, Adriana Simoni Lucato, Silvia Amélia Vedovello, Heloísa Cristina Valdrighi, Mário Vedovello Filho, Lourenço Correr-Sobrinho
2013 Brazilian Dental Journal  
The aim of this study was to evaluate the shear bond strength (SBS) of metallic orthodontic brackets bonded to bovine teeth using light-activated or chemically activated composite resins. One hundred and twenty bovine mandibular incisors were divided into 6 groups (n=20), according to the bonding materials: Transbond XT (T); Enforce Dual (ED); Enforce chemical (EC); Enforce Light-activated (EL); Concise Orthodontic (C); and RelyX Unicem Capsule (UN). Metallic brackets were positioned and firmly
more » ... bonded to the teeth. Light-activation for T, ED, EL and UN was carried out with four exposures on each side of the bracket with 20 s total exposure times using XL2500 (3M ESPE). EC and C were chemically cured. Next, all specimens were stored in deionized water at 37 °C for 24 h. The shear bond strength was carried out at a crosshead speed of 1.0 mm/min. Data were subjected to one-way ANOVA and Tukey's test (α=0.05). The adhesive remnant index (ARI) was evaluated at 8× magnification. C (17.72±4.45) presented significantly higher SBS means (in MPa) than the other groups (p<0.05), followed by EC (11.97±5.77) and ED (10.57±1.32). EL (5.39±1.06) and UN (4.32±1.98) showed the lowest SBS means, while T (9.09±2.56) showed intermediate values. For ARI, there was a predominance of score 0 for EC, C and UN, and score 3 for T, ED and EL. In conclusion, the activation mode influenced the SBS.
doi:10.1590/0103-6440201302342 pmid:24474295 fatcat:o4sw66dhqjgi5ebzoaisv3j4ki