The purpose of this study was to evaluate the bond strength and adaptabilily of three endodontic root canal sealers to human root canal dentin after preconditioning with NaOCl, EDTA and Laser irradiation. Ninety recent extracted human permanent mandibular premolars were used in this study. The crowns of all teeth were removed at the level of cementoenamel junction and all root canals were instrumented with crown down technique. The coronal 6mm of the canal was enlarged using Gates-Glidden drills and the canal irrigated with NaOCL between each files. The teeth were divided into three equal groups according to the dentin treatment (n=JO); group A: received NaOcl as final irrigation group B: received EDTA as final irrigation and group C: irradiated with diode laser. Each group was subdivided into three equal subgroups (n=10) accordiirg to.the endodontic sealer using during obturation (AH Plus, ReokoSeal Automix and Epiphany). The push out test was performed and data (MPa) were analysed statistically by ANOVA and Pair-wise Newman Keuls;(P < 0,05): Results: Overall, the resin based sealer (AH Plus) had the highest bond strength that the methacrylate based sealer (Epiphany) and Silicone based sealer (ReokoSeal Automix).