A Comparison of the Safety of Various Intracanal Irrigation Systems

Objective: To comparatively evaluate the relative safety of apical negative pressure, sonic, manual syringe, piezoelectric ultrasonic with concurrent irrigant delivered through the ultrasonic cannula and pressure-suction irrigation systems by measuring the apical extrusion of the irrigating solution.

Method: Twenty two (22) single canal, extracted human teeth with mature apices free of fracture were cleaned and shaped to at least a master apical file size #35 with 4 % taper. Teeth were secured through lid of a scintillation vial to collect extruded solution. A programmable mechanical syringe pump was used to deliver controlled amounts of solution at a constant flow. The irrigation systems used according to the manufacturer's instructions were Endovac Micro Cannula (Apical Negative Pressure - Group 1), Endovac Macro Cannula (Apical Negative Pressure-Group 2), EndoActivator (Sonic Irrigation - Group 3) Manual Syringe (Positive Pressure - Group 4), Piezoelectric Ultrasonic Irrigation System (Group 5), Rinsendo (Pressure-Suction Technology - Group 6). A fluid recovery trap was used to collect irrigant expressed coronally.

Results: A 2-tailed Paired t–test was used to test for differences between pairs of group means. Statistical significance was set at p<0.05. The Apical Negative Pressure Groups 1 and 2 were the only ones, which did not extrude irrigating solution into the collection vial (Periradicular Recovery Trap). There was a statistically significant difference between them and all remaining groups. EndoActivator (Group 3) extruded significantly less irrigant compared to Group 4, Group 5 and Group 6 (p<.05). Manual irrigation (Group 4) extruded significantly less solution than pressure-suction technology system(Group 6), but significantly more than the Apical Negative Pressure (Group 1-2) and Sonic group (Group 3).

Conclusion: No irrigant was extruded using apical negative pressure and a minimal amount was extruded using the sonic group.