title: Antibacterial Efficacy of Different Concentrations of Sodium Hypochlorite Gel and Solution onEnterococcus faecalisBiofilm.
abstract: BACKGROUND
  Thisin vitrostudy compared the antibacterial efficacy of 2.5% sodium hypochlorite gel and 2.5% and 5.25% sodium hypochlorite solutions onEnterococcus faecalis(E. faecalis) biofilm.
  
  
  METHODS
  The root canals of 60 extracted human single-rooted teeth were contaminated withE. faecalisand incubated for 6 weeks. The samples were randomly assigned to three experimental groups and one control group (n=15). The study protocol in the experimental groups consisted of injection of 5 mL of each irrigant into the root canals. Samples were collected from the root canal walls and 1:10 serial dilutions were prepared and added to Muller Hinton Agar (MHA) plates and incubated at 37°C for 48 h. A classic colony counting technique was used for determining vitalE. faecalisbacterial counts in MHA plates. The Kruskal-Wallis test was used for statistical analysis of the data. The level of significance was set at 0.05.
  
  
  RESULTS
  The antibacterial effect of the irrigants in all three experimental groups was significantly greater than the control group (P<0.05), with no significant difference between 2.5% and 5.25% NaOCl solutions (P>0.05). The effect of 2.5% and 5.25% NaOCl solutions were significantly superior to 2.5% NaOCl gel (P<0.05).
  
  
  CONCLUSIONS
  Under the limitations of this study, 2.5% NaOCl gel was effective in reducingE. faecaliscounts; however this effect was less than that of NaOCl solutions.
authors: Dental and Periodontal Research Center, Dental School, Tabriz University of Medical Sciences, Tabriz, Iran.
authors: Vahid
authors: V
authors: Zand
authors: Dental and Periodontal Research Center, Dental School, Tabriz University of Medical Sciences, Tabriz, Iran.
authors: Mehrdad
authors: M
authors: Lotfi
authors: Microbiology Department, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran.
authors: Mohammad Hosein
authors: MH
authors: Soroush
authors: Dental and Periodontal Research Center, Department of Endodontics, Student Research Committee, Dental School, Tabriz University of Medical Sciences, Tabriz, Iran.
authors: Amir Ardalan
authors: AA
authors: Abdollahi
authors: Private Practice, Tabriz, Iran.
authors: Mehdi
authors: M
authors: Sadeghi
authors: Dental and Periodontal Research Center, Dental School, Tabriz University of Medical Sciences, Tabriz, Iran.
authors: Ali
authors: A
authors: Mojadadi
keywords: Antibacterial; Biofilm; Enterococcus Faecalis; Sodium Hypochlorite