Apically Extruded Debris Using Passive Ultrasonic Irrigation Associated with Different Root Canal Irrigants

The present study evaluated the amount of apically extruded debris after chemo-mechanical preparation (CMP) associated with passive ultrasonic irrigation (PUI) using four different root canal irrigants, namely, 6% sodium hypochlorite (NaOCl), 2% chlorhexidine gel + saline solution (2% CHXg+SS), 2% chlorhexidine solution (2% CHXs) and SS alone. Sixty mandibular premolars with single straight root canals were selected and randomly assigned into 4 groups (n=15) according to the root canal irrigant used as follows: G1 (PUI + NaOCl), G2 (PUI + CHXg+SS), G3 (PUI+CHXs) and G4 (PUI+SS). Reciproc® R25 files (25/.08) were used during CMP and the debris extruded from each tooth were collected in pre-weighted Eppendorf tubes and dried. The average weight of debris was assessed by using an analytical microbalance. Data were statistically analysed by using ANOVA and post-hoc Tukey's test (a=0.05). Debris extrusion was observed in all groups, irrespective of the root canal irrigating, with 2% CHXg + SS being associated with lower debris extrusion compared to other irrigants (p<0.05). No significant differences were observed between 6% NaOCl, 2% CHXs and SS. In conclusion, passive ultrasonic irrigation did not completely prevent apically extrusion of debris. PUI performed with 2% chlorhexidine gel + saline solution significantly minimized debris extrusion compared to 6% sodium hypochlorite, chlorhexidine solution and saline solution.