title: Antibacterial Activity of Diode Laser and Sodium Hypochlorite in Enterococcus Faecalis-Contaminated Root Canals.
abstract: BACKGROUND
  The aim of the present in vitro study was to evaluate the disinfection ability of 980-nm diode laser in comparison with sodium hypochlorite (NaOCl) as a common root canal irrigant in canals infected with Enterococcus faecalis (E. faecalis).
  
  
  METHODS
  The root canals of 18 extracted single-rooted premolars were prepared by rotary system. After decoronation, the roots were autoclaved. One specimen was chosen for the negative control, and the remaining teeth were incubated with E. faecalis suspension for two weeks. Subsequently, one specimen was selected as the positive control and the remaining samples were divided into two groups (n=8). The samples of the first group were irrigated with 5.25% NaOCl and the second group were treated with a 980-nm diode laser. Microbial samples were taken from the root canals and bacterial cultivation was carried out. The average value and the standard deviation of colony-forming units (CFU) of each specimen were measured using descriptive statistics. The student's t-test was used to compare the reduction in CFU in each group. The equality of variance of CFU was measured by the Levene's test.
  
  
  RESULTS
  NaOCl resulted in 99.87% removal of the bacteria and showed significantly more antibacterial effect compared to the 980-nm diode laser which led to 96.56% bacterial reduction (P<0.05).
  
  
  CONCLUSIONS
  Although 5.25% NaOCl seems to reduce E. faecalis more effectively, the diode laser also reduced the bacterial count. Therefore a 980-nm diode laser could be considered as a complementary disinfection method in root canal treatment.
authors: Department of Endodontics, Dental School, Tehran University of Medical Sciences, International Campus, Tehran, Iran.
authors: Khosrow
authors: K
authors: Sohrabi
authors: Department of Endodontics, Dental School, Tehran University of Medical Sciences, International Campus, Tehran, Iran.
authors: Aidin
authors: A
authors: Sooratgar
authors: General Dentist, Tehran, Iran.
authors: Kaveh
authors: K
authors: Zolfagharnasab
authors: Department of Epidemiology, Tehran University of Medical Sciences, International Campus, Tehran, Iran.
authors: Mohammad Javad
authors: MJ
authors: Kharazifard
authors: Department of Endodontics, Dental School, Tehran University of Medical Sciences, International Campus, Tehran, Iran.
authors: Farzaneh
authors: F
authors: Afkhami
keywords: Diode Laser; Enterococcus faecalis; Root Canal Disinfection; Root Canal Irrigant