Avaliação por microtração da resistência de união de diferentes sistemas adesivos ao esmalte humano

Abstract

The objective of this work was to evaluate the microtensile bond strength to the human enamel of three different adhesive systems. Twenty one not prepared third molar human teeth (n=21) had been divided in three groups, with seven teeth in each group (n=7), as the used adhesive system: SB - Adper Single Bond 2 (3M/ESPE, St Paul, MN, the USA); CL - Clearfil IF Bond (Dental Kuraray, Osaka, Japan); XE - XENO III (Dentsply, Detrey, Konstanz, Germany). The teeth used were unbroken and none of them were prepared. After the adhesive protocols, a composed resin nanoparticule (Filtek Z 350, 3M/ESPE, St. Paul, MN,USA) were placed in 4 (four) layers of 1,0mm, separately and lightcured per 40 seconds. For the microtensile bond test the samples had been cut parallel to the long axle of teeth, with constant irrigation until getting beams of 1 (one) mm2 of area. For the microtensile bond strength test the samples were tested in a Universal Testing Machine (EMIC DL 2000, São José dos Pinhais, Paraná, Brasil) with a cross head speed of 0,5 speed of mm/min. Observing the normality of distribution of the data, the analysis of variance and the Test of Tukey (p<0,05) indicated differences between the groups. The average values (MPa) for each group had been: SB: 16,12 ± 7.64a; CB: 11,30 ± 5,47ab e, XE: 8,65 ± 6,19b. The results had indicated that the step of acid conditioning of the human enamel resulted in force of significantly bigger union of the Adper Single Bond 2 (3M/ESPE, St Paul, MN, the USA) in relation to XENO III (Dentsply, Detrey, Konstanz, Germany), that is of only step.