title: The Antibacterial Efficacy of Photo-Activated Disinfection, Chlorhexidine and Sodium Hypochlorite in Infected Root Canals: An in Vitro Study.
abstract: BACKGROUND
  This study compared the efficacy of light-activated low-power laser, 2% chlorhexidine (CHX) and 2.5% NaOCl in eliminating Enterococcus faecalis (E. faecalis) from the root canal system.
  
  
  METHODS
  The root canals of 60 maxillary central incisors were contaminated with E. faecalis and then the bacteria were incubated for 24 h. All the root canals were instrumented in a crown-down manner with #4 and 3 Gates-Glidden drills, followed by RaCe rotary files (40/0.10, 35/0.08, and 30/0.06). The samples were randomly assigned to three experimental groups and one control group (n=15). In the control group no intervention was made. In the photo-activated disinfection (PAD) group, laser therapy was undertaken with diode laser beams (with an output power of 100 mW/cm(2)) for 120 sec. For the other two experimental groups, root canals were irrigated either with 5 mL of 2% CHX or 2.5% NaOCl solutions, respectively. The Kruskal-Wallis test was used to compare the CFU values of the bacteria and post-hoc Bonferroni test was used for pairwise comparisons. The level of significance was set at 0.05.
  
  
  RESULTS
  The inhibition of bacterial growth in all the experimental groups was significantly superior to the control group (P<0.05). There was no significant difference between the effect of PAD and 2% CHX (P=0.05). The effect of 2.5% NaOCl was significantly better than that of the PAD technique (P<0.001). In addition, 2.5% NaOCl was significantly better than 2% CHX (P=0.007).
  
  
  CONCLUSIONS
  Photodynamic therapy was effective in reducing the E. faecalis counts in comparison with the control group, but 2.5% NaOCl solution was the most effective protocol.
authors.affiliation: Department of Endodontics, Dental and Periodontal Research Center, Dental School, Tabriz University of Medical Sciences, Tabriz, Iran;
authors.forename: Mohammad
authors.initials: M
authors.lastname: Samiei
authors.affiliation: Department of Endodontics, Dental and Periodontal Research Center, Dental School, Tabriz University of Medical Sciences, Tabriz, Iran;
authors.forename: Shahriar
authors.initials: S
authors.lastname: Shahi
authors.affiliation: Department of Endodontics, Dental and Periodontal Research Center, Dental School, Tabriz University of Medical Sciences, Tabriz, Iran;
authors.forename: Amir Ardalan
authors.initials: AA
authors.lastname: Abdollahi
authors.affiliation: Department of Endodontics, Dental and Periodontal Research Center, Dental School, Tabriz University of Medical Sciences, Tabriz, Iran;
authors.forename: Mahsa
authors.initials: M
authors.lastname: Eskandarinezhad
authors.affiliation: Department of Prosthodontics, Dental and Periodontal Research Center, Dental School, Tabriz University of Medical Sciences, Tabriz, Iran;
authors.forename: Ramin
authors.initials: R
authors.lastname: Negahdari
authors.affiliation: Private Practice, Urmia, Iran.
authors.forename: Zahra
authors.initials: Z
authors.lastname: Pakseresht
keywords: Enterococcus faecalis; Laser; Photo-Activated Disinfection; Photodynamic Therapy; Sodium Hypochlorite