title: A comparison between effect of photodynamic therapy by LED and calcium hydroxide therapy for root canal disinfection against Enterococcus faecalis: A randomized controlled trial.
abstract: BACKGROUND
  Insufficient root canal disinfection is one of the main reasons for persistent periapical pathology. Photodynamic therapy (PDT) has been proven effective in disinfecting infected root canals. The aim of this study was to evaluate the antimicrobial effect of photo activated disinfection (PAD) when using toluidine blue as photosensitizer and a LED lamp after the conventional treatment, and comparing it with calcium hydroxide therapy in vivo.
  
  
  METHODS
  This clinical trial includes 20 patients with molars requiring endodontic retreatment. After the conventional treatment, first microbiological samples were obtained using sterile rotary ProTaper F2 file and 3 paper points and transferred to a microbiology laboratory. Group 1 (n=10) specimens underwent PAD with photosensitizer (PS) solution (0.1mg/mL TB) and irradiation with Fotosan light emitting diode (LED) lamp (635nm, 200mW/cm2) for 60s. Creamy Ca(OH)2 paste was used in group 2 (n=10) for two weeks. A second sample was then obtained. The samples were cultured and then bacterial colonies were counted. Data included number of colony forming units (CFUs) before and after treatments, analyzed by t-test and analysis of covariance (ANCOVA) using SPSS vs.18.
  
  
  RESULTS
  A significant difference between results of before and after treatment of both groups (calcium hydroxide therapy p=0.02<0.05, PAD p<0.0001) indicated the efficacy of both treatments. The mean numbers for log 10CFUs/mL before calcium hydroxide therapy and PAD with LED irradiation was 10.1968 and 11.3773. After treatment, the mean numbers were 9.4202 and 8.3772, respectively. The difference in results after treatment between groups was significant (p=0.01<0.05) and indicate that PAD was more effective.
  
  
  CONCLUSIONS
  PAD and calcium hydroxide therapy, as auxiliary methods adjunct to conventional root canal therapy, are both effective in root canal disinfection. In comparison with calcium hydroxide therapy, PAD leads to a greater reduction in enterococcus faecalis number in the infected root canals.
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: Endodontic Department, Dental School, Shahid Beheshti University of Medical Science, Tehran, Iran.
authors.forename: Hengameh
authors.initials: H
authors.lastname: Ashraf
authors.affiliation: Endodontic Department, Dental School, Hamedan University of Medical Science, Hamedan, Iran. Electronic address: drrahmati@ymail.com.
authors.forename: Afsaneh
authors.initials: A
authors.lastname: Rahmati
authors.affiliation: University of Texas Health Science Center, Houston, United States of America.
authors.forename: Neda
authors.initials: N
authors.lastname: Amini
mesh_terms: D002126:Calcium Hydroxide / Q000627:therapeutic use*; D002470:Cell Survival; D003786:Dental Pulp Cavity / Q000382:microbiology*; D004203:Disinfection / Q000379:methods; D013293:Enterococcus faecalis / Q000187:drug effects*; D006801:Humans; D010778:Photochemotherapy / Q000379:methods*; D017319:Photosensitizing Agents / Q000627:therapeutic use*; D014048:Tolonium Chloride / Q000627:therapeutic use*
chemical_list: D017319:Photosensitizing Agents; D014048:Tolonium Chloride; D002126:Calcium Hydroxide