Effects of retreatment kits and laser activated irrigation on root canal retreatment

The aim of this study was to evaluate the efficacy of Er:Yag laser actived irrigation in extracted teeth on root canal retreatment process using two different rotary instrument systems. Extracted mandibular premolar teeth were decoronated and instrumented up to ProTaper Universal(Dentsply Maillefer, Ballaigues, Switzerland) F3 file, and then filled with ProTaper Universal F3 guttapercha and AH Plus (Dentsply De Trey GmbH, Konstanz, Germany)sealer. Root canal fillings were removed with ProTaper Retreatment(Dentsply Maillefer, Ballaigues, Switzerland) kit for half of the samples and Mtwo Retreatment(VDW, Munich, Germany) kit for the other half. Conventional irrigation was used to half of the samples in both groups and actived irrigation with PIPS was applied to the remaining half. Four study groups were obtained in total and root canal filling removal activities were evaluated. Samples were sectioned longitudinally and photographed with a stereomicroscope at 8X magnification. The percentage of remaining filling material on coronal, middle and apical canal walls was calculated. For statistical evaluation two-way analysis of variance for root canal retreatment technique groups and root canal regions was performed while one way analysis of variance was performed for root canal retreatment techniques used in each root canal region were encountered. Er:Yag laser activation with PIPS was more effective in removing canal filling material than conventional irrigation. There was no significant difference in canal filling removal efficiency between the ProTaper R and Mtwo R rotary kits. The amount of residuel filling material was seen in the apical, middle and coronal regions of root in the order of higher to lower, respectively, and the difference between them was statistically significant. According to the results of our study, we think that Er:Yag laser activated irrigation with PIPS can be used as an effective method for root canal filling removal in coronal and middle part of the root in endodontic retreatment. Keywords: Retreatment, Laser activated irrigation, Pips