title: The evaluation of cultivable microbiota profile in patients with secondary endodontic infection before and after photo-activated disinfection.
abstract: BACKGROUND
  Secondary/persistent endodontic infection can be the outcome of failure of endodontic treatment. Photo-activated disinfection (PAD) can be a useful adjunct to mechanical and antimicrobial agents in eliminating endopathogenic microorganisms. In this study, we evaluated the effect of PAD on diversity and count of microbiota related to secondary/persistent endodontic infections.
  
  
  METHODS
  Root canal samples were taken using sterile paper points from the root canals of 14 patients with secondary/persistent endodontic infections after removing the root-canal filling materials. PAD was performed on teeth with toluidine blue O (TBO) in combination with diode laser. Then re-sampling was conducted from the canal root using sterile paper points and transferred to transport medium. The samples were plated and pure cultures of the target microorganisms were then isolated and identified by analytical profile index (API®20A) assays and 16S ribosomal RNA gene sequencing.
  
  
  RESULTS
  Before TBO-PAD, a total of 31 cultivable isolates could be retrieved; 25.8% of the isolated species were obligate anaerobic or microphilics including Veillonella parvula, Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans, Propionibacterium acnes, and Lactobacillus acidophilus, and 74.2% of the isolated species were facultative anaerobic such as Enterococcus faecalis, Actinomyces naeslundii, L. rhamnosus, L. casei, Streptococcus sanguinis, S. mitis, and Candida albicans. According to this in vivo study, the diversity and count of microbiota in root canal-treated teeth were decreased after TBO-PAD, so that E. faecalis, V. parvula, and C. albicans were the microorganisms that recovered after PAD.
  
  
  CONCLUSIONS
  TBO-PAD is an effective approach that exhibited anti-microbial potential activity against microbiota involved in secondary/persistent endodontic infection.
authors.affiliation: Department of Microbiology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Maryam
authors.initials: M
authors.lastname: Pourhajibagher
authors.affiliation: Private Practice, Tehran, Iran.
authors.forename: Roghayeh
authors.initials: R
authors.lastname: Ghorbanzadeh
authors.affiliation: Department of Surgical Sciences and Integrated Diagnostics, University of Genoa, Italy.
authors.forename: Steven
authors.initials: S
authors.lastname: Parker
authors.affiliation: Laser Research Center, Dentistry Research Institute, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Nasim
authors.initials: N
authors.lastname: Chiniforush
authors.affiliation: Department of Microbiology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran; Laser Research Center, Dentistry Research Institute, Tehran University of Medical Sciences, Tehran, Iran; Dental Research Center, Dentistry Research Institute, Tehran University of Medical Sciences, Tehran, Iran. Electronic address: abahador@sina.tums.ac.ir.
authors.forename: Abbas
authors.initials: A
authors.lastname: Bahador
mesh_terms: D000328:Adult; D016976:Aggregatibacter actinomycetemcomitans / Q000302:isolation & purification; D001424:Bacterial Infections / Q000382:microbiology* / Q000628:therapy*; D003786:Dental Pulp Cavity / Q000382:microbiology*; D004203:Disinfection / Q000379:methods; D013293:Enterococcus faecalis / Q000302:isolation & purification; D005260:Female; D006801:Humans; D054023:Lasers, Semiconductor / Q000627:therapeutic use; D008297:Male; D064307:Microbiota / Q000187:drug effects / Q000528:radiation effects; D010778:Photochemotherapy / Q000379:methods*; D017319:Photosensitizing Agents / Q000627:therapeutic use; D016966:Porphyromonas gingivalis / Q000302:isolation & purification*; D011671:Pulpitis / Q000382:microbiology* / Q000628:therapy*; D014048:Tolonium Chloride / Q000627:therapeutic use; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D017319:Photosensitizing Agents; D014048:Tolonium Chloride
keywords: Diode laser; Facultative anaerobic bacteria; Microbial diversity; Obligate anaerobic bacteria; Photo-activated disinfection; Secondary/persistent endodontic infection; Toluidine blue O