Do chlorhexidine and ethanol improve bond strength and durability of adhesion of fiber posts inside the root canal?

Abstract

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. 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. 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). 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. PT of the root canal using ethanol seems to facilitate adhesive luting of fiber posts with the tested adhesive system and luting cements.