Comparative Evaluation of Irrigants on Sealer Penetration: An in vitro Confocal Laser Scanning Microscopy Study

Introduction: Effective smear layer removal enhances sealer penetration in endodontics. Chelating agents vary in their efficacy, influencing treatment outcomes. In this study, the depth of penetration of AH Plus and Bio-C root canal sealers into dentinal structures was analysed using confocal laser scanning microscopy (CLSM), following the application of four final irrigants: 17% EDTA, 20% citric acid, 0.2% chitosan, and 5% fulvic acid. Methods: Ninety-six single-rooted human premolars were prepared and irrigated with sodium hypochlorite. Final irrigation used one of four agents: 17% EDTA, 20% citric acid, 0.2% chitosan, or 5% fulvic acid, followed by sonic activation. Canals were obturated with either AH Plus or Bio-C sealer labelled with Rhodamine B dye. Samples underwent incubation and were sliced at the apical third for analysis under CLSM. Data were evaluated using repeated measures ANOVA and Tukey’s post hoc test (p < 0.05). Results: The combination of chitosan and Bio-C sealer showed the highest mean sealer penetration (973.82 ± 85.09 µm), demonstrating a significantly higher value compared to the other groups (p < 0.001). The combination of citric acid and Bio-C exhibited the least sealer penetration. Conclusion: Chitosan and fulvic acid significantly enhance the penetration of bioceramic sealers, improving the sealing quality and potential success of endodontic treatment.