In vitro antimicrobial activity of sodium hypochlorite and chlorhexidine against selected single-species biofilms

• Published in: International endodontic journal 2006-11, Vol.39 (11), p.878-885
• Main Authors: Sena, N. T., Gomes, B. P. F. A., Vianna, M. E., Berber, V. B., Zaia, A. A., Ferraz, C. C. R., Souza-Filho, F. J.
• Format: Article
• Language: English
• Subjects: Anti-Infective Agents, Local - administration & dosage; Anti-Infective Agents, Local - pharmacology; Bacteriological Techniques; biofilm; Biofilms - drug effects; Candida albicans; Candida albicans - drug effects; chlorhexidine; Chlorhexidine - administration & dosage; Chlorhexidine - pharmacology; Colony Count, Microbial; Dentistry; Disinfectants - administration & dosage; Disinfectants - pharmacology; Dose-Response Relationship, Drug; endodontics; Enterococcus faecalis; Enterococcus faecalis - drug effects; Fusobacterium nucleatum; Fusobacterium nucleatum - drug effects; Humans; Materials Testing; micro-organisms; Porphyromonas endodontalis; Porphyromonas endodontalis - drug effects; Porphyromonas gingivalis; Porphyromonas gingivalis - drug effects; Prevotella intermedia; Prevotella intermedia - drug effects; Root Canal Irrigants - administration & dosage; Root Canal Irrigants - pharmacology; sodium hypochlorite; Sodium Hypochlorite - administration & dosage; Sodium Hypochlorite - pharmacology; Staphylococcus aureus; Staphylococcus aureus - drug effects; Time Factors
• ISSN: 0143-2885; 1365-2591
• DOI: 10.1111/j.1365-2591.2006.01161.x

Aim  To investigate the antimicrobial activity of 2.5% and 5.25% sodium hypochlorite and 2.0% chlorhexidine gel and liquid as endodontic‐irrigating substances against selected single‐species biofilms. Methods  Single‐species biofilms of Enterococcus faecalis, Staphylococcus aureus, Candida albicans, Prevotella intermedia, Porphyromonas gingivalis, Porphyromonas endodontalis and Fusobacterium nucleatum were generated on a cellulose nitrate membrane placed on agar medium. The biofilms were then immersed in the endodontic‐irrigating substances for 30 s and also for 5, 10, 15, 30 and 60 min, with and without mechanical agitation. Sterile saline was used as control. After each time period, the membrane filters were then transferred to tubes containing 2 mL of fresh broth medium plus neutralizers (in order to prevent the residual action of the tested substances). The micro‐organisms were suspended using a vortex, and the inoculum was serially diluted 10‐fold. Aliquots of the dilutions were plated on 5% sheep blood agar medium, and incubated under adequate gaseous conditions. Colony‐forming units were calculated. The samples were compared using the Friedman and Tukey test, when necessary, at a significance level of P