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.
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.