title: The disinfecting efficacy of root canals with laser photodynamic therapy.
abstract: BACKGROUND
  Infecting microorganisms of the root canals are difficult to eliminate during endodontic treatment. In this study the effect of root canal disinfection with photodynamic therapy (PDT) at different time intervals in comparison to 2.5% sodium hypochlorite (NaOCl) irrigation and passive ultrasonic irrigation (PUI) in extracted teeth colonized with Enterococcus faecalis and Candida albicans was tested to assess which treatment reaches the best disinfection rate.
  
  
  METHODS
  One hundred and fifty-six extracted single-rooted teeth were collected, sterilized, and incubated with Enterococcus faecalis (ATCC 29212) and Candida albicans (ATCC 60193). The two groups were further divided into 6 groups depending on the treatment mode; HELBO(®)Endo Blue photosensitizer dye application followed by HELBO laser irradiation, with the output power 100 mW and emission of 660 nm, for a 1, 3 and 5 minutes, irrigation with 2.5% NaOCl, 10 second PUI with 2.5% NaOCl and control group. Flow cytometry and scanning electron microscopic (SEM) analysis were used to determine the effectiveness of the different disinfecting methods.
  
  
  RESULTS
  The different disinfecting methods had a significantly different effect on the percent of dead cells (p<0.001). A statistical significance of dead cells between organisms (p<0.001) was observed. Interaction between the disinfecting method and both of organisms had shown the statistical significance (p=0.045). Percent of dead cells in treatment groups were significantly higher compared to control group for both organisms (p<0.001).
  
  
  CONCLUSIONS
  PUI still remains the most effective method for disinfection of infected root canals in endodontics compared to hand instrumentation for both microorganisms. SEM analysis only confirmed the results. Other results ex vivo suggested that prolonging the time from 1 to 5 minutes of PDT increased the number of killed microorganisms significantly, therefore longer times of photodynamic therapy were recommended. Irrigation with 2.5% NaOCl showed similar results to 5 min irradiation.
authors.affiliation: Faculty of Medicine Prishtina, Kosovo.
authors.forename: Aliu
authors.initials: A
authors.lastname: Xhevdet
authors.affiliation: Institute of Microbiology and Immunology, Zaloska 4, Ljubljana, Slovenia.
authors.forename: David
authors.initials: D
authors.lastname: Stubljar
authors.affiliation: Department for Dental Diseases and Morphology of Dental Organ, Medical Faculty, Vrazov Trg 2, Ljubljana, Slovenia.
authors.forename: Igor
authors.initials: I
authors.lastname: Kriznar
authors.affiliation: Medical Faculty of Osijek, Josipa Hutlera 4, Osijek, Croatia.
authors.forename: Tomislav
authors.initials: T
authors.lastname: Jukic
authors.affiliation: Institute of Microbiology and Immunology, Zaloska 4, Ljubljana, Slovenia.
authors.forename: Miha
authors.initials: M
authors.lastname: Skvarc
authors.affiliation: Institute of Cell Biology, Lipiceva Ulica 2, Ljubljana, Slovenia.
authors.forename: Peter
authors.initials: P
authors.lastname: Veranic
authors.affiliation: Institute of Microbiology and Immunology, Zaloska 4, Ljubljana, Slovenia.
authors.forename: Alojz
authors.initials: A
authors.lastname: Ihan
keywords: Candida albicans; enterococcus faecalis; infection; root canal