Efficacy of syringe irrigation, RinsEndo (R) and passive ultrasonic irrigation in removing debris from irregularities in root canals with different apical sizes

P>Aim To compare of the efficacy of syringe irrigation, RinsEndo (R) (Durr Dental, Bietigheim, Germany) and passive ultrasonic irrigation (PUI) in the removal of dentinal debris from simulated irregularities in root canals with different apical sizes. Methodology Thirty extracted human pre-molars were randomly divided into three groups (n = 10) followed by root canal preparation with rotary FlexMaster (R) NiTi instruments (VDW, Munich, Germany) to size 30, 0.02 taper (group 1), size 40, 0.02 taper (group 2) or size 50, 0.02 taper (group 3). The teeth were split longitudinally, and a standard groove and three hemispherical-shaped cavities were cut into the root canal halves. Grooves and cavities were filled with dentinal debris before each irrigation procedure and the root halves were reassembled. In all groups three different irrigation procedures were performed with 30 mL NaOCl (1%) and (i) syringe, (ii) RinsEndo (R) and (iii) PUI. The amount of remaining debris was evaluated under a microscope with 30x magnification and a four score system. The data were analysed with a non-parametric analysis of covariance and multiple comparisons using the Tukey adjustment (P = 0.05). Results Passive ultrasonic irrigation removed debris significantly better from the artificial canal irregularities than RinsEndo (R) and syringe irrigation irrespective of the root canal diameter. Only in group 1 (30, 0.02 taper) the difference between PUI and RinsEndo (R) was not statistically significant (P = 0.99). RinsEndo (R) demonstrated significantly better results than syringe irrigation in all groups (P < 0.001). Conclusions Ultrasonic irrigation is more effective than syringe irrigation or RinsEndo (R) in removing debris from artificial extensions in straight root canals.