Effects of the application techniques of self-adhesive resin cements on the interfacial integrity and bond strength of fiber posts to dentin

Objective: to evaluate the influence of an application technique of a glass-fiber post using self-adhesive resin cements on the push-out bond strength and the presence of bubbles in the root thirds. the cements were either applied according to the manufacturer's instruction or using a commercial delivering system (centrix),at which the cement pastes were collected and applied after manipulation. material and methods: self-adhesive resin cements (relyx u200/3m espe-u200; maxcem elite/kerr-max; clearfil sa cement/kuraray-csa) and a conventional cement (relyx arc/3m espe-arc) were used to cement a post and applied either based on the manufacturer's instructions or using a centrix syringe to deliver the cements directly onto the post of choice,or directly into canal. the roots were scanned with a micro-computed tomography (μct) and then sectioned into nine 1-mm thick slices for a push-out bond strength test. the μct images showed the percentage of bubbles in the root thirds (cervical,medium,and apical). data were analyzed with three-way anova/tukey (α=0.05). results: triple interaction was not significant (p>0.05). the interaction “material” vs “root third” was not significant. a significant interaction was observed between “material” vs “application technique” (p<0.05). for arc,u200,and max,significantly lower percentages of bubbles were observed when the centrix syringe delivered the cements. equivalent percentages of voids were observed for csa,irrespective of the application technique (p>0.05). significantly higher bond strength was observed when the self-adhesive resin cements were applied using the centrix delivery system,in comparison with the manufacturer's instructions (p<0.05). bond strength varied with the root third: cervical>medium>apical (p<0.05). no correlations were found between the bond strength and voids. conclusions: bond strength and voids are negatively influenced by the conventional application technique for luting fiber posts. the delivery system (centrix) seems to produce better results when cementing fiber posts. © 2016,faculdade de odontologia de bauru. all rights reserved.