RESUMO
OBJECTIVES: The aim was to investigate the effects of chlorhexidine and ethanol pretreatment of the root canal on push-out bond strengths and durability of adhesion of fiber posts luted with two different adhesive strategies. MATERIALS AND METHODS: One hundred twenty human anterior teeth were endodontically treated. After post space preparation, the root canals were irrigated using 1 % sodium hypochlorite (NaOCl) applied with passive ultrasonic irrigation followed by distilled water (control). In pretreatment (PT) group, chlorhexidine (CHX) root canals were irrigated using 2 % chlorhexidine; and in the PT group, 99 % ethanol was used prior application of the luting agent. Two different post-and-luting systems with an etch-and-rinse (CX) adhesive approach (n = 60) and a self-adhesive resin cement (RX; n = 60) were inserted into the root canals. Bond strengths were evaluated initially and after thermocycling and storage for 6 months using push-out tests. RESULTS: Bond strength was significantly affected by the adhesive strategy (p < 0.0005), the pretreatment (p < 0.0005) and the location inside the root canal (p < 0.0005; repeated measurement ANOVA). Ethanol significantly increased bond strengths irrespective of the luting agent used compared to the control and CHX group (p < 0.05; Tukey's B). CONCLUSION: Ethanol significantly increased bond strength of the CX and the RX system inside the root canal and could be recommended as a final rinse for luting fiber posts using an ethanol-based etch-and-rinse adhesive system or self-adhesive resin cement. CLINICAL RELEVANCE: PT of the root canal using ethanol seems to facilitate adhesive luting of fiber posts with the tested adhesive system and luting cements.