Although previous studies demonstrated efficacy of sonic and ultrasonic systems on debris and CH removal8,10,28, sufficient information is not yet available in the literature concerning XP-endo Finisher31 and laser-activated irrigation (LAI). Therefore, the aim of this study was to compare the effect of XP-endo Finisher, sonic, ultrasonic and LAI and conventional syringe irrigation techniques in removing CH from simulated lateral irregularities on the root canal wall. The null hypotheses were that the removal of CH was not affected by irrigation technique  or the  section of root canal (third).