Objective: This study assessed the push-out bond strength (POBS) of an epoxy resin-based sealer in oval-shaped root canals after a final irrigation protocol using XP-endo Finisher and ultrasonic activation. Materials and methods: Thirty oval-shaped human root canals were prepared with Reciproc R25 and a final irrigation regimen using 5.25% sodium hypochlorite and 17% ethylenediaminetetraacetic acid (EDTA) was performed. The teeth were divided into three groups (n = 10) according to the final irrigation activation technique: no activation (control), ultrasonic activation and XP-endo Finisher activation. Specimens were filled only with AH Plus sealer and the POBS test was used to measure the bond strength between the root canal dentine and AH Plus sealer. The data obtained from the POBS test were analysed using two-way analysis of variance and Tukey post-hoc tests (P 0.05). Results: The POBS values decreased from the coronal to the apical direction (P 0.05). There was a significant association between the activation technique and the root canal third (P 0.05). In the coronal and middle third, XP-endo Finisher and ultrasonic activation showed higher POBS than the control group (P 0.05). In the apical third, XP-endo Finisher showed higher POBS than ultrasonic activation (P 0.05) and the control group (P 0.001). Ultrasonic activation also showed higher POBS values in the apical third when compared to the control group (P 0.05). Conclusions: The activation of root canal irrigants influenced POBS of root canal sealers in the different root thirds of oval-shaped canals. The use of XP-endo Finisher file resulted in better POBS than ultrasonic activation in the apical third. Keywords: root canal irrigants, shear strength, ultrasonic activation