Efficacy of irrigation ultrasonic passive in removal of calcium hydroxide paste from root canals

INTRODUCTION: Remnants of calcium hydroxide (Ca(OH)2) can interfere in the quality of endodontic treatment. AIM: Evaluate the efficacy of Passive Ultrasonic Irrigation (PUI) associated with the conventional technique in removing intracanal medication Ca(OH)2-based. METHODOLOGY : Thirty monoradiculares anterior human teeth were used. The root canals were prepared with manual instruments type K and filled with intracanal medication Ca(OH)2-based containing CMCP and propylene glycol. After 7 days, Ca(OH)2 was removed of all root canal with a manual instrument and irrigation of the 1% NaOCl with syringe. The specimens were randomly divided into two groups (n=12) according to the final irrigation: Manual Irrigation - manual agitation of 17% EDTA and 1% NaOCl irrigation; PUI - ultrasonic agitation of NaOCl 1% (3 activations of 20s) followed by activation of 17% EDTA for 1 min. The control group (n=6) received no medication. All the specimens were cleaved and the amount of Ca(OH)2 remaining was calculated with the auxiliary of estereomicroscrópio (20×). Kruskall-Wallis tests and Wilcoxon tests were used to evaluate the percentage of Ca(OH)2 remaining. RESULT: The group of PUI showed statistically the lowers percentages of Ca(OH)2 when compared to group of Manual Irrigation, independently, of thirds analyzed (P < 0.05). The apical showed the higher amount of residual medication, in both groups (P < 0.05). CONCLUSION: The association of PUI with the conventional technique proved to be more efficient in removing medication of Ca(OH)2-based that the combination of Manual irrigation with conventional technique.