title: Comparative evaluation of calcium hypochlorite and sodium hypochlorite associated with passive ultrasonic irrigation on antimicrobial activity of a root canal system infected with Enterococcus faecalis: an in vitro study.
abstract: BACKGROUND
  The purpose of this study was to compare in vitro the effectiveness of calcium hypochlorite (Ca[OCl]2) and sodium hypochlorite (NaOCl) associated with passive ultrasonic irrigation in root canals of bovine teeth infected with Enterococcus faecalis.
  
  
  METHODS
  The root canals of 60 single-rooted bovine extracted teeth were enlarged up to a file 45, autoclaved, inoculated with Enterococcus faecalis, and incubated for 30 days. The samples were divided into 6 groups (n = 10) according to the protocol for decontamination: G1: no treatment; G2: distilled water; G3: 2.5% NaOCl; G4: 2.5% Ca(OCl)2; G5: 2.5% NaOCl with ultrasonic activation; and G6: 2.5% Ca(OCl)2 with ultrasonic activation (US). Microbiological testing (colony-forming unit [CFU] counting) was performed to evaluate and show, respectively, the effectiveness of the proposed treatments. Data were subjected to 1-way analysis of variance followed by the post hoc Tukey test (α = 0.05).
  
  
  RESULTS
  Groups 1 and 2 showed the highest mean contamination (3.26 log10 CFU/mL and 2.69 log10 CFU/mL, respectively), which was statistically different from all other groups (P < .05). Group 6 (Ca[OCl]2 + US) showed the lowest mean contamination (1.00 log10 CFU/mL), with no statistically significant difference found in groups 3 (NaOCl), 4 (Ca[OCl]2), and 5 (NaOCl + US) (P < .05).
  
  
  CONCLUSIONS
  Ca(OCl)2 as well as passive ultrasonic irrigation can aid in chemomechanical preparation, contributing in a significant way to the reduction of microbial content during root canal treatment.
authors.affiliation: School of Dentistry, University of Passo Fundo, Passo Fundo, Rio Grande do Sul, Brazil.
authors.forename: Ana Paula
authors.initials: AP
authors.lastname: de Almeida
authors.affiliation: School of Dentistry, University of Passo Fundo, Passo Fundo, Rio Grande do Sul, Brazil. Electronic address: matheus292@yahoo.com.br.
authors.forename: Matheus Albino
authors.initials: MA
authors.lastname: Souza
authors.affiliation: School of Dentistry, University of Passo Fundo, Passo Fundo, Rio Grande do Sul, Brazil.
authors.forename: Daniela Cristina
authors.initials: DC
authors.lastname: Miyagaki
authors.affiliation: School of Dentistry, University of Passo Fundo, Passo Fundo, Rio Grande do Sul, Brazil.
authors.forename: Yuri
authors.initials: Y
authors.lastname: Dal Bello
authors.affiliation: School of Dentistry, University of Passo Fundo, Passo Fundo, Rio Grande do Sul, Brazil; School of Dentistry, University of Illinois at Chicago, Chicago, Illinois.
authors.forename: Doglas
authors.initials: D
authors.lastname: Cecchin
authors.affiliation: School of Dentistry, University of Passo Fundo, Passo Fundo, Rio Grande do Sul, Brazil; School of Dentistry, University of Illinois at Chicago, Chicago, Illinois.
authors.forename: Ana Paula
authors.initials: AP
authors.lastname: Farina
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D058491:Bacterial Load / Q000187:drug effects; D001431:Bacteriological Techniques; D017610:Calcium Compounds / Q000494:pharmacology*; D002417:Cattle; D003786:Dental Pulp Cavity / Q000382:microbiology*; D013293:Enterococcus faecalis / Q000187:drug effects*; D012388:Root Canal Irrigants / Q000494:pharmacology*; D018915:Root Canal Preparation / Q000379:methods; D012973:Sodium Hypochlorite / Q000494:pharmacology*; D007507:Therapeutic Irrigation / Q000379:methods*; D014464:Ultrasonic Therapy / Q000379:methods*
chemical_list: D000900:Anti-Bacterial Agents; D017610:Calcium Compounds; D012388:Root Canal Irrigants; C004488:calcium hypochlorite; D012973:Sodium Hypochlorite
keywords: Calcium hypochlorite; Enterococcus faecalis; passive ultrasonic irrigation; sodium hypochlorite