Permeabilidade dentinária e morfologia da interface adesiva de diferentes sistemas adesivos

Abstract

ObjectiveCompare dentine permeability of different adhesive systems with and without hydrophobic resin. Analyze the influence of pulpal pressure on the morphology of the adhesive interface. MethodsFor the permeability assay, teeth were randomly allocated in 4 groups (n=9), according to the adhesive systems: Futurabond U (Voco) self‐etch; Futurabond U etch‐and‐rinse; Scotchbond 1XT (3M‐Espe); Easybond (3M‐Espe) with subsequent application of an hydrophobic resin [Adhesive; Scotchbond Multipurpose system (3M‐Espe)]. Hydraulic conductance of each specimen was measured on a permeability apparatus. To characterize the morphology of the adhesive interface in scanning electron microscope, 3 specimens from each group subjected to pulpal pressure were used, and new specimens (n=3) were prepared without pulpal pressure, according to the same adhesive system, forming the 4 groups described before. Permeability of the different adhesive systems was compared with Anova and Tukey post‐hoc (p<0.05). Permeability before and after the hydrophobic resin layer was compared with a paired t student test for repeated measures. ResultsPermeability was significantly lower with Futurabond U self‐etch when compared to the etch‐and‐rinse groups (p<0.05), both before and after hydrophobic resin layer application. Hydrophobic resin layer lead to a significant reduction on the permeability for all adhesive systems (p<0.05). Hybrid layer was not identified on the self‐etch groups as opposed to the etch‐and‐rinse groups. Adhesive interface had alterations when the pulpal pressure was applied. ConclusionHydrophobic resin layer reduced the permeability in all adhesive systems tested. Structural defects were present in all groups when the adhesive procedures were performed under pulpal pressure.