Effects of different electrical currents on the application of adhesive systems to dentin

Abstract

The aim of this study is verify the effect of different electrical currents in the quality of sealing dentin by evaluating of the bond strength of conventional and self-etch adhesive system in samples stored in water for 24 hours. Human third molars caries free will be used, which will be divided into groups according to the adhesive system and electrical current used (n = 5). The adhesive systems used will be two self-etch (Clearfil SE Bond, Kuraray and Adper Easy One, 3M ESPE) and one conventional (Single Bond Adper 2, 3M ESPE). Each adhesive system will be applied under eight different electrical currents (0, 5¼A, 10¼A, 15¼A, 20¼A, 25¼A, 30¼A and 35¼A) and photoacured by a LED with 800mW/cm2 irradiance (UltraLume 5, Ultradent Products, South Jordan, UT , USA). Then blocks will be made on dentin using the composite Filtek Z350 XT (3M ESPE) in increments of 2mm and photocured for 20 seconds. After the samples will be cut longitudinally in 1mm slices and perpendicular to obtain sticks 1mm² that will be stored in distilled water at 37°C for 24 hours and then submitted to microtensile bond strength test in a Universal machine (Instron 4411) at a crosshead speed of 0.5mm/min. The fracture patterns will be analyzed and classified as cohesive failure (dentin/composite), adhesive or mixed. The values of bond strength will be submitted to two-way analysis of variance and the means compared by Tukey's test (5%). (AU)