(PR106) Influence of Different Irrigation Protocols in Endodontic Retreatment and Their Impact on the Adhesion of Bioceramic Sealer

Objective: The influence of passive ultrasonic irrigation (PUI) and activated irrigation with XP-endo Finisher (XPF) on the removal of resin sealer in retreatment and the impact of the remaining sealer on the bond strength (BS) of the bioceramic sealer was evaluated using the push out and SEM. Materials and

Methods: Pre-molars with flat canals were prepared with R25 and obturated with AH Plus. The specimens were thermocycling and then retreated with deobturation and repreparation with R50 and irrigation with different protocols (n=20): syringe and needle (SA), PUI, and XPF. Specimens were reobturated with GuttaFlow bioseal varying the filling technique (n=10): lateral condensation (LC) and single cone (SC). The specimens were sectioned in 2 mm slices in each root third for push-out test and analysis of bonding interface on SEM.

Results: ANOVA and Tukey showed higher BS (MPa) for PUI (3.46±0.97) and XPF (3.28±0.91) (p>0.05), different from SA (2.73±0.60) (p < 0.05). In the interaction of filling technique and root third, it was evidenced that in LC the cervical (4.10±0.75) and middle (4.06±0.68) thirds were similar (p>0.05) to each other and different from the apical (2.77±0.45). For SC, the apical third (2.13±0.32) showed the lowest value (p < 0.05). The analysis in SEM showed greater penetration of GuttaFlow bioseal in the LC.

Conclusion: It was concluded that PUI and XPF, associated with lateral condensation, favored the penetration of the sealer in the dentinal tubules and the bond strength of GuttaFlow bioseal to dentin.