title: A comparison of the antibacterial activity of the two methods of photodynamic therapy (using diode laser 810 nm and LED lamp 630 nm) against Enterococcus faecalis in extracted human anterior teeth.
abstract: BACKGROUND
  Failure of endodontic treatment is usually due to an inadequate disinfection of the root canal system. Enterococcus faecalis has been widely used as a valuable microbiological marker for in-vitro studies because of its ability to colonize in a biofilm like style in root canals, invading dentinal tubules and resistance to some endodontic treatments. The aim of this study was to investigate the antibacterial effects of two methods of photodynamic therapy using a light emitting diode lamp (LED lamp, 630 nm) and a diode laser (810 nm) on E. faecalis biofilms in anterior extracted human teeth.
  
  
  METHODS
  Fifty six single-rooted extracted teeth were used in this study. After routine root canal cleansing, shaping and sterilization, the teeth were incubated with E. faecalis for a period of two weeks. Teeth were then divided into two experimental groups (nu=23) and two control groups (nu=5). Teeth in one experimental group were exposed to a diode laser (810 nm), and in the other group samples were exposed to a LED lamp (630 nm). Intracanal bacterial sampling was done, and bacterial survival rate was then evaluated for each group.
  
  
  RESULTS
  The Colony Forming Unit (CFU) in LED group (log10 CFUs=4.88±0.82) was significantly lower than the laser group (log CFUs=5.49±0.71) (p value=0.021). CFUs in positive control group (Log10 CFUs=10.96±0.44) were significantly higher than the treatment group (p˂0.001). No bacterial colony was found in negative control group.
  
  
  CONCLUSIONS
  The results of this research show that photodynamic therapy could be an effective supplement in root canal disinfection. PDT using LED lamp was more effective than diode laser 810 nm in reducing CFUs of E. faecalis in human teeth.
authors.affiliation: Laser Application in Medical Sciences Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors.forename: Mohammad
authors.initials: M
authors.lastname: Asnaashari
authors.affiliation: Department of Laser, Dental School, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors.forename: Seyed Masoud
authors.initials: SM
authors.lastname: Mojahedi
authors.affiliation: Dentist, Laser Application in Medical Sciences Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors.forename: Zahra
authors.initials: Z
authors.lastname: Asadi
authors.affiliation: Department of Oral and Maxillofacial Medicine, School of Dentistry, Qom University of Medical Sciences, Qom, Iran. Electronic address: saranazazari@yahoo.com.
authors.forename: Saranaz
authors.initials: S
authors.lastname: Azari-Marhabi
authors.affiliation: Laser Application in Medical Sciences Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors.forename: Alireza
authors.initials: A
authors.lastname: Maleki
mesh_terms: D000328:Adult; D018441:Biofilms / Q000254:growth & development* / Q000528:radiation effects; D002470:Cell Survival / Q000187:drug effects; D003786:Dental Pulp Cavity / Q000187:drug effects / Q000382:microbiology*; D004203:Disinfection / Q000295:instrumentation; D013293:Enterococcus faecalis / Q000187:drug effects* / Q000502:physiology; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005260:Female; D006801:Humans; D066298:In Vitro Techniques; D054023:Lasers, Semiconductor / Q000627:therapeutic use*; D008029:Lighting / Q000295:instrumentation; D008297:Male; D010778:Photochemotherapy / Q000295:instrumentation*; D017319:Photosensitizing Agents / Q000008:administration & dosage; D018915:Root Canal Preparation / Q000295:instrumentation*; D012666:Semiconductors; D014081:Tooth Extraction
chemical_list: D017319:Photosensitizing Agents
keywords: Diode laser; Enterococcus faecalis; LED lamp; Photodynamic therapy