5 mm/minute until debonding. The values were obtained in KgF and were converted in MPa, which involved dividing the force (KgF) by the adhesive interface (cm2). The normality of the data was evaluated by Shapiro-Wilk and Kolmogorov-Smirnov tests. In addition, a one-way analysis of variance (ANOVA) was performed http://www.selleckchem.com/products/Gefitinib.html to compare the experimental and control group. Finally, a Tukey post-hoc test was conducted for multiple pairwise comparisons (��=.05). Morphological analysis of the cavosurface enamel on SEM Four specimens for each group were observed in an SEM for the morphology analysis of the cavosurface enamel submitted to different surface treatments. The teeth were prepared in a similar way as in the adhesive procedure. The etching with 35% phosphoric acid of the enamel was performed by 15 s.

Then, the surface was washed for 15 s and air dried. In group 2, the primer was applied according to the manufacturer��s instructions. It was removed after 20 s and washed with ethanol and acetone for 10 s in each solution, alternating the solutions for 1 min. In group 3, the acid etching was performed for 15 s prior to the application of the primer. In addition, the surface was washed for 15 s and air dried. Finally, the primer was applied and removed in the same way as in group 2. All specimens were submitted to dehydration in ascending concentrations of ethanol (30%, 50%, 70%, 90%, and 100%). The samples were subsequently gold sputtered (Desk II, Denton Vacuun Inc., NJ, USA) and analyzed using an SEM (JSM �C 5600 �C JEOL USA, Inc., Peabody, MA, USA).

The etching pattern was performed with a descriptive analysis related to the morphologic characteristics. RESULTS Microshear Bond Strength The results collected regarding bond strength obtained through the microshear test are presented in Table 1. The group in which the self-etching adhesive method was used presented statistically similar results to the group in which the adhesive procedure using the etch-and-rinse adhesive system was performed. When the etching with 35% phosphoric acid was carried out prior to the application of the self-etching adhesive system, the bond strength was significantly greater than the other groups. Table 1. Means (MPa) and standard deviations of experimental groups.

Analysis of the morphology of the conditioned surface through SEM When a cavosurface region without conditioning was observed, the surface appeared smooth, without any possibility of visualization of the enamel prisms constituting the region (Figures 1a and and1b).1b). However, when this surface was etched with 35% phosphoric Brefeldin_A acid for 15 s, the presence of the enamel prisms was noted in the longitudinal cut with the etching of the whole central region of the prisms and slight etching of the peripheral region (Figures 2a and and2b2b). Figure 1. View of grounded cavosurface enamel without acid etching. (A ��1000; B ��3000). Figure 2. Cavosurface enamel after acid-etch with 35% phosphoric acid.