Effectiveness of different ırrigation solution activation techniques on filling material removal following retreatment

Objective: This study aimed to assess the effectiveness of XP-endo Finisher, EndoActivator, Er, Cr: YSGG laser active irrigation, passive ultrasonic activation techniques in removing filling remnants from root canals after root canal retreatment procedures. Method: Seventy five single-rooted mandibular premolar teeth were instrumented with Resiproc 40 (# 40.06) instruments and obturated with gutta-percha and AH Plus sealer using the continuous wave of condensation technique. After storage at 37ºC and 100% humidity for 1 week, the specimens were retreated with the ProTaper Universal Retreatment and ProTaper Next (X2-X5) NiTi instruments for the removal of filling material. Then teeth were randomly divided into five groups (n꞊15), and the activation processes were applied: group 1 conventional needle irrigation, group 2 EndoActivator, group 3 passive ultrasonic activation, group 4 XP-endo Finisher and group 5 Er, Cr: YSGG laser active irrigation. Conventional needle irrigation was used as the control group. The teeth were sectioned and steromicroscopy images were taken. The images were analysed using Image J software regarding the area of residual root filling. In addition, a scanning electron microscope images were taken from 3 samples from each group. Oneway ANOVA, Tukey, Wilcoxon and Friedman tests were performed for statistical analysis. Results: The filling materials removal efficacy in the apical region and the total canal area the XP-endo Finisher, EndoActivator, passive ultrasonic activation groups were süperior to conventional needle irrigation group (P < 0.05) and there was no statistically significant difference between the conventional needle irrigation and Er, Cr: YSGG laser active irrigation groups (P > 0.05). There was a statistically significant difference between the Er, Cr: YSGG laser active irrigation group and passive ultrasonic activation groups in the total canal area (P <0.05). In the middle and koronal region of the root canal the conventional irrigation group remove less filling material then other groups (P < 0.05) and there was no statistically significant difference between the other groups (P> 0.05). Conclusions: In all groups there is residual substance in the root canals. The apical regions of the channels contain more residual filler than the middle and coronal regions.