Effects of Different Final Irrigating Solutions on Depth of Sealer Penetration into Dentinal Tubules

Aim: To evaluate the maximum depth of sealer penetration into dentinal tubules at the coronal, middle, and apical third of root canals, following the use of different final irrigation solutions. Materials and methods: Eighty freshly extracted mandibular premolars were selected for the study. After decoronation, instrumentation of samples was done using Protaper universal rotary file system till F4. During shaping and cleaning of root canal, 5.25% concentration of sodium hypochlorite (NaOCl) was used for irrigation. The samples were then randomly divided into four groups (n = 20) depending on the final irrigating solution used. Group I: 17% aqueous ethylenediaminetetraacetic acid (MA) (aq. EDTA); group II: 10% citric acid (CA); group III: 5% maleic acid; group IV: 5.25% conc. NaOCl. Passive ultrasonic irrigation (PUI) was used to activate each final irrigating solution. The samples were obturated using warm lateral condensation technique with guttapercha coated with AH plus sealer mixed with rhodamine B dye. Confocal laser scanning microscopy (CLSM) examined the sealer penetration depth. Results: The Kruskal–Wallis analysis results showed that there was a significant difference in the maximum depth of sealer penetration among all groups in all sections (p < 0.05). The coronal sections of the root canals in each group showed a significantly higher depth of sealer penetration than did the apical and middle sections (p < 0.05). Conclusion: A combination of 17% aq. EDTA and PUI used for final irrigation proved to be more effective for sealer penetration into the dentinal tubules. Clinical significance: Final irrigation protocol followed is of paramount importance in achieving complete disinfection within the root canal, and also the penetration of sealer serves as an indicator of the extent to which the smear layer was removed.