title: Efficacy of antimicrobial solutions against polymicrobial root canal biofilm.
abstract: OBJECTIVE
  To evaluate the antibiofilm activity of 2.5% sodium hypochlorite (NaOCl), 2% chlorhexidine (CHX), 2% alexidine (ALX) and 0.2% cetrimide (CTR) alone and in combination on mature polymicrobial root canal biofilms on human dentine using confocal laser scanning microscopy (CLSM).
  
  
  METHODS
  Twenty-eight human dentine specimens were infected for 21 days with microbial samples collected from infected root canals of three volunteers. Antibiofilm activity of the irrigating solutions was evaluated after 3 min of contact time under CLSM. For quantification purposes, bioimage_L software was used. The variables evaluated were the log10of total biovolume (μm3) and percentage of live cells (green) population. Statistical analysis of both variables was performed using an anova test and a post hoc Duncan test to determine significant clusters amongst groups. The variable green population percentage was previously subjected to the normalized Anscombe transformation.
  
  
  RESULTS
  The NaOCl group had a total biovolume and percentage of live cells significantly lower than the other groups (P ˂ 0.001). The addition of 0.2% CTR significantly increased the antimicrobial effect of 2% CHX (P ˂ 0.001). There were no significant differences between 0.2% CTR, 2% ALX and the combination of both (P ˂ 0.05).
  
  
  CONCLUSIONS
  Overall, 2.5% NaOCl dissolved and killed bacteria significantly more efficiently when used against polymicrobial mature biofilm on human dentine. Cetrimide improved the antimicrobial activity of chlorhexidine and alexidine.
authors.affiliation: Department of Paediatric Dentistry, University of Granada, Granada, Spain.
authors.forename: M
authors.initials: M
authors.lastname: Ruiz-Linares
authors.affiliation: University of Granada, Granada, Spain.
authors.forename: B
authors.initials: B
authors.lastname: Aguado-Pérez
authors.affiliation: Department of Preventive Dentistry, University of Granada, Granada, Spain.
authors.forename: P
authors.initials: P
authors.lastname: Baca
authors.affiliation: Department of Microbiology, University of Granada, Granada, Spain.
authors.forename: M T
authors.initials: MT
authors.lastname: Arias-Moliz
authors.affiliation: Department of Dental Pathology and Therapeutics, School of Dentistry, University of Granada, Granada, Spain.
authors.forename: C M
authors.initials: CM
authors.lastname: Ferrer-Luque
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001645:Biguanides / Q000494:pharmacology; D018441:Biofilms / Q000187:drug effects*; D000077286:Cetrimonium; D002593:Cetrimonium Compounds / Q000494:pharmacology; D002710:Chlorhexidine / Q000494:pharmacology; D003804:Dentin / Q000382:microbiology*; D006801:Humans; D012390:Root Canal Therapy; D012973:Sodium Hypochlorite / Q000494:pharmacology
chemical_list: D000900:Anti-Bacterial Agents; D001645:Biguanides; D002593:Cetrimonium Compounds; D012973:Sodium Hypochlorite; C001570:alexidine; D002710:Chlorhexidine; D000077286:Cetrimonium
keywords: alexidine; cetrimide; chlorhexidine; dentine; polymicrobial biofilm; sodium hypochlorite