Influência de diferentes cimentos endodônticos na resistência de união de pinos de fibra de vidro à dentina radicular.

Abstract

The study aimed to test if the composition of four different endodontic sealers influence the adhesive properties of a resin cement used for luting glass fiber posts to root canal dentin in all root thirds. Sixty bovine roots were divided into four groups according to the endodontic sealer (n=15): ZOE - zinc oxide eugenol-based; CH - calcium hydroxide-based; ER - epoxy resin-based; and BC - bioceramic-based. The canals were prepared using passive step-back technique and sealed with gutta-percha and endodontic sealer. Then were prepared, cleaned, dried and posts were cemented with self-adhesive dual-cure resin cement after one week. Roots (n=10) were cross-sectioned to obtain two discs for each canal third: cervical, middle and apical. These slices were submitted to a push-out test. Cross sections, same as the push-out slices, were evaluated under scanning electron microscopy (SEM) (n=2) and confocal laser scanning microscopy (without post cementation) (n=2). Longitudinal sections (n=1) were evaluated under SEM. Data were analyzed using ANOVA and Bonferroni t-test (p<0.05). The variable endodontic sealer affected the push-out bond strength values (p<0.001), as well as the variable root third (p<0.001). Significant interaction was found between the endodontic sealer and root third variables (p<0.001). The BC group was the only to present significant differences compared to the other groups, with the lowest bond strength values. It can be concluded that the endodontic sealer may influence the adhesion of glass fiber posts luted with self-adhesive resin cement to root canal dentin; and that the apical third presents lower bond strength values.