Objective: To evaluate the efficacy of the EDDY, Ultra X, and XP-endo Finisher irrigation activation systems in removing residual bioceramic root canal sealer after endodontic retreatment using scanning electron microscopy (SEM).

Methods: Single-rooted teeth subjected to endodontic retreatment were evaluated and allocated to three groups according to the irrigation activation method: EDDY, Ultra X, and XP-endo Finisher. Following the irrigation protocol, the roots were prepared for SEM evaluation at 2000× magnification. Root canal surfaces were assessed in the apical, middle, and coronal thirds using a five-point ordinal scale to determine the amount of residual material. Two independent and blinded observers performed the evaluations, and the mean score was calculated for each tooth. Differences among activation methods within each root canal third were analyzed using the Kruskal–Wallis test, while differences among root canal thirds within each group were analyzed using the Friedman test. Statistical significance was set at 0.05.

Results: No statistically significant differences were found among EDDY, Ultra X, and XP-endo Finisher in any of the evaluated root canal thirds. In the apical third, the median scores were 3.0 (2.0–5.0), 4.5 (1.5–5.0), and 3.75 (2.0–5.0), respectively (p=0.203); in the middle third, 2.75 (1.0–4.5), 3.0 (2.0–4.5), and 2.75 (1.5–4.5), respectively (p=0.592); and in the coronal third, 2.5 (1.0–4.5), 3.0 (1.0–4.0), and 2.0 (1.0–5.0), respectively (p=0.797). Significant differences among root canal thirds were observed within the Ultra X (p=0.025) and XP-endo Finisher (p=0.005) groups, but not within the EDDY group (p=0.272).

Conclusions: Within the experimental conditions of this study, none of the evaluated irrigation activation methods demonstrated statistically superior efficacy in removing residual bioceramic root canal sealer from the apical, middle, or coronal thirds.