Antimicrobial efficacy of 4.2% sodium hypochlorite adjusted to pH 12, 7.5, and 6.5 in infected human root canals

• Published in: Oral surgery, oral medicine, oral pathology, oral radiology and endodontics Vol. 107; no. 2; pp. 295 - 298
• Main Authors: Mercade, Montse, DDS, PhD, Duran-Sindreu, Fernando, DDS, PhD, Kuttler, Sergio, DDS, MSc, Roig, Miguel, MD, DDS, PhD, Durany, Nuria, BSc, PhD
• Format: Journal Article
• Language: English
• Published: New York, NY Mosby, Inc 01.02.2009; Elsevier
• Subjects: Anti-Infective Agents, Local - chemistry; Anti-Infective Agents, Local - pharmacology; Anti-Infective Agents, Local - therapeutic use; Biological and medical sciences; Dental Pulp Cavity - microbiology; Dentistry; Enterococcus faecalis - drug effects; Gram-Positive Bacterial Infections - drug therapy; Humans; Hydrogen-Ion Concentration; Medical sciences; Nephelometry and Turbidimetry; Otorhinolaryngology. Stomatology; Root Canal Irrigants - chemistry; Root Canal Irrigants - pharmacology; Root Canal Irrigants - therapeutic use; Sodium Hypochlorite - chemistry; Sodium Hypochlorite - pharmacology; Sodium Hypochlorite - therapeutic use; Surgery; Human; Infection; Sodium; Efficiency; Dental canal; pH; Antimicrobial agent
• ISSN: 1079-2104; 1528-395X
• DOI: 10.1016/j.tripleo.2008.05.006

Objective The purpose of this study was to determine the antimicrobial efficacy of sodium hypochlorite adjusted to pH 12, 7.5, and 6.5 in human root canals infected by Enterococcus faecalis. Study design One hundred sixty-five human single-rooted teeth were prepared and inoculated with E. faecalis for 48 h. Teeth were divided into 3 experimental groups according to the irrigation pattern used: group 1, 4.2% NaOCl pH 12; group 2, 4.2% NaOCl pH 7.5; and group 3, 4.2% NaOCl pH 6.5. Samples from the root canals were collected, and bacterial growth was analyzed by turbidity of the culture medium. Results None of the irrigating solutions used in this study demonstrated 100% effectiveness against E. faecalis . The antibacterial effectiveness of 4.2% NaOCl at pH 6.5 was significantly increased ( P = .03) compared with 4.2% NaOCl at pH 12 (chi-squared test: P < .05). Conclusion Bactericidal activity of NaOCl solution is enhanced by weak acidification of 4.2% NaOCl solution at pH 6.5.