effect of polymerization mode of two adhesive systems on push-out bond strength of fi ber post to different regions of root canal dentin

background: a few studies have investigated the effect of the activation mode of adhesive systems on bond strength of fi ber posts to root canal dentin. this study investigated the push-out bond strengths of a glass fi ber post to different root canal regions with the use of two adhesives with light- and dual-cure polymerization modes. materials and methods: in this in vitro study, 40 maxillary central incisors were decoronated at cement-enamel junction with 15 ± 1 mm root length. after root canal therapy and post space preparations, they were randomly divided into four groups. post spaces were treated with four different adhesives: excite, excite dual cure single component (dsc), self-etch adhesive (adhese), and adhese dual-cure. then the fi ber-reinforced composite (frc) post, postec plus, was cemented with dual-cure resin cement, variolink ii. the roots were cut into three 2-mm-thick slices. push-out tests were performed with a universal testing machine at a crosshead speed of 0.5 mm/min. the mode of failures was determined under a stereomicroscope. data were analyzed by three-way analysis of variance (anova) and tukey test was conducted to compare post hoc with p < 0.05 as the level of signifi cance. results: the highest bond strength was obtained for adhese dual-cure (15.54 ± 6.90 mpa) and the lowest was obtained for excite light-cure (10.07 ± 7.45 mpa) and only the bond strength between these two adhesives had signifi cant difference ( p = 0.02). bond strength decreased from the coronal to the apical in all groups and this was signifi cant in excite (group 1) and adhese (group 3) ( p < 0.001). in apical regions, bond strength of dual-cure adhesives was signifi cantly higher than light-cure adhesives ( p < 0.001). conclusion: push-out bond strength of fi ber post to different regions of root canal dentin was affected by both adhesive systems and their polymerization modes. key words: adhesive, bond strength, fi ber post, polymerization mode