title: Synergistic antibacterial activity of chlorhexidine and hydrogen peroxide against Enterococcus faecalis.
abstract: The aim of the present study was to compare the in vitro antibacterial activity of common root canal irrigants with a combination technique against intratubular Enterococcus faecalis. Seventy-five human single-rooted teeth were selected and their crowns and root-ends were removed to obtain specimens 5 mm in length. The specimens were contaminated with E. faecalis and divided into five experimental groups (n = 15). These groups were irrigated with 2% chlorhexidine (CHX), 3% hydrogen peroxide (H2O2), 5.25% sodium hypochlorite (NaOCl), CHX/H2O2 and sterile saline (control). Surface and deep dentinal chips were collected for each sample. After incubation, the numbers of colony-forming units (CFUs) were counted. The Kruskal-Wallis and Mann-Whitney U tests were used for statistical analysis (α = 0.05). In the surface dentin, CHX, NaOCl, and CHX/H2O2 had significantly higher antibacterial activity than H2O2 (P < 0.05). In the deep dentin, NaOCl and CHX/H2O2 had significantly higher antibacterial activity than CHX and H2O2 (P < 0.05). CHX/H2O2 had similar antibacterial effectiveness to NaOCl in both surface and deep dentinal tubules. This combination can be considered a potentially useful irrigant for root canal treatment.
authors.affiliation: Torabinejad Dental Research Center, Department of Endodontics, School of Dentistry, Isfahan University of Medical Sciences.
authors.forename: Seyedmohsen
authors.initials: S
authors.lastname: Hasheminia
authors.forename: Ali R
authors.initials: AR
authors.lastname: Farhad
authors.forename: Masoud
authors.initials: M
authors.lastname: Saatchi
authors.forename: Morteza
authors.initials: M
authors.lastname: Rajabzadeh
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D002710:Chlorhexidine / Q000494:pharmacology*; D003786:Dental Pulp Cavity / Q000382:microbiology; D004357:Drug Synergism; D013293:Enterococcus faecalis / Q000187:drug effects*; D006801:Humans; D006861:Hydrogen Peroxide / Q000494:pharmacology*; D008826:Microbial Sensitivity Tests; D012388:Root Canal Irrigants / Q000494:pharmacology*
chemical_list: D000900:Anti-Bacterial Agents; D012388:Root Canal Irrigants; D006861:Hydrogen Peroxide; D002710:Chlorhexidine