Effect of irrigants using ultrasonics on intracanal calcium hydroxide removal – an in vitro comparative evaluation

Aim: To evaluate the efficacy of various irrigating solutions on calcium hydroxide (Apex cal and RC cal) removal with the use of ultrasonics. Methods: The root canals of 120 single-rooted maxillary central incisors were prepared using the stepback technique. The teeth were decoronated and split longitudinally. After filling, the two halves of roots were reassembled with sticky wax and each group was further divided into four subgroups according to the irrigating solution: Smear Clear, 10% citric acid, 5% EDTA and 3% NaOCl. Evaluation for cleanliness was done under a microscope with ×12.5 magnification. Statistical analysis was done with Kruskal Wallis and Mann Whitney tests at 5% level of significance. Results: There was no statistically significant difference (p>0.05) for calcium hydroxide (Apex Cal and RC Cal) removal by different irrigants. There were more residues in the apical groove than in the coronal groove (p<0.05). Conclusions: When the different irrigants were compared at coronal and apical levels, Smear Clear and citric acid were more effective in calcium hydroxide removal than EDTA and NaOCl.