Investigation of the effect of intracanal disinfection techniques in reducing of the amount of enterococcus faecalis and candida albicans in infected root canals during retreatment by using PCR

Aim: The aim of this in vivo study was to compare the effect of passive ultrasonic irrigation, manual dynamic activation and photodynamic therapy in reducing microorganism load in endodontic retreatment of teeth with periradicular lesion by using polymerase chain reaction (PCR). Methodology: Thirty-six endodontically treated root canals with apical periodontitis were selected for this study. Teeth were randomly divided into 3 groups according to the supplementary disinfection techniques used: Passive ultrasonic irrigation (PUI), Manual dynamic activation (MDA) and Photodynamic therapy (PDT). Microbiological samples were taken after removal of gutta-percha (S1), chemomechanical preparation (S2) and supplementary disinfection techniques (S3). The levels of E. faecalis and C. albicans in these samples were measured by using PCR. Results: None of the disinfection techniques was completely removed microorganism from root canals. No significant differences were observed between groups in terms of removing of E. faecalis (p>0.05). All disinfection techniques were removed E. faecalis in similar ratios. There was a significant difference only between PUI and MDA groups in terms of removing C. albicans (p=0.043). In MDA group, C. albicans was removed in smaller ratio compared to PUI group. FDT was the only effective technique that reduced the amount of both microorganism. Conclusion: Chemomechanical preparation was not enough to remove all microorganism from root canals alone. Supplementary disinfection techniques should be used in single visit endodontic retreatment cases.