Effects of Internal Bleaching on the Adhesion of Glass-Fiber Posts

OBJECTIVE We evaluated the effects of internal bleaching on the adhesion of glass-fiber posts (GFPs) luted with different resin cements. METHODS Forty extracted human single-root teeth were endodontically treated and divided into four groups (n=10): G1- conventional resin cement (CRC); G2- self-adhesive resin cement (SARC); G3- bleaching + CRC; and G4- bleaching + SARC. Specimens were sectioned transversally into three slices to perform the push-out test at the coronal, middle and apical regions of the root canals. Data were analyzed using analysis of variance and Tukey's test (p<0.05). RESULTS The push-out bond strength of GFPs luted with SARC after bleaching (G4) was significantly lower than that of the other groups (p<0.001). We found no statistically significant differences in push-out bond strength among the other groups. SIGNIFICANCE Internal bleaching reduced the adhesion of GFPs luted with SARC. The adhesion of GFPs luted with CRC was not decreased after bleaching.