Antimicrobial Effectiveness of Photodynamic Therapy, 5% Sodium Hypochlorite and 2% Chlorhexidine Gluconate in Root Canal Treated Teeth: A Clinical Study

Aim: To evaluate the effectiveness of photodynamic therapy (PDT), sodium hypochlorite (NaOCl) and chlorhexidine gluconate (CHO) in the endodontic re-treatment in the removing of microorganisms from previously filled infected root canals. Materials and Methods: The study samples consist of 54 root canal treated anterior teeth with apical periodontitis were randomly divided into three groups according to the disinfection protocol. Microbiological samples from the root canals were collected after removing the gutta-percha (S1) and following the endodontic re-treatment (S2) with either 5% NaOCl, 2% CHO or PDT procedure for 1 minute. Microbiological samples were cultivated on selective plates to assess the presence or absence of microbial growth and determine the average reduction of viable microorganisms. Results: Significant reduction in the total bacterial count in all the groups at post treatment (P < .001). PDT provided statistically higher (99.74%) elimination of Enterococcus faecalis in comparison to NaOCl (95%) and CHO (88%). Conclusions: The use of PDT in endodontic re-treatment led to the significant reduction of the remaining bacterial species. So, PDT can be used for routine endodontic disinfection in failed root canal cases.