Dentin Inhibits the Antibacterial Effect of New and Conventional Endodontic Irrigants

• Published in: Journal of endodontics Vol. 39; no. 3; pp. 406 - 410
• Main Authors: Morgental, Renata Dornelles, DDS, MS, Singh, Aruna, BDS, Sappal, Harkeet, DDS, Kopper, Patrícia Maria Poli, DDS, MS, PhD, Vier-Pelisser, Fabiana Vieira, DDS, MS, PhD, Peters, Ove A., DMD, MS, PhD
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01-03-2013
• Subjects: Animals; Anti-Infective Agents, Local - antagonists & inhibitors; Anti-Infective Agents, Local - pharmacology; Antibacterial effect; Biguanides - antagonists & inhibitors; Biguanides - chemistry; Biguanides - pharmacology; Cattle; chlorhexidine; Chlorhexidine - antagonists & inhibitors; Chlorhexidine - pharmacology; Colony Count, Microbial; Dentin - physiology; Dentistry; Edetic Acid - pharmacology; EDTA; Endocrinology & Metabolism; endodontic irrigation; Enterococcus faecalis; Enterococcus faecalis - drug effects; Polymers - chemistry; Polymers - pharmacology; QMiX; Root Canal Irrigants - chemistry; Root Canal Irrigants - pharmacology; sodium hypochlorite; Sodium Hypochlorite - antagonists & inhibitors; Sodium Hypochlorite - pharmacology; Enterococcus faecalis; Antibacterial effect; endodontic irrigation; chlorhexidine; EDTA; sodium hypochlorite; QMiX
• ISSN: 0099-2399; 1878-3554
• DOI: 10.1016/j.joen.2012.10.028

Abstract Introduction This in vitro study aimed to compare the antibacterial effect of a new irrigant, QMiX, with that of conventional irrigation solutions in the presence or absence of dentin powder. Methods Dentin powder was prepared from bovine incisors and sterilized. The following irrigants were tested against Enterococcus faecalis (ATCC 29212): 6% sodium hypochlorite (NaOCl), 1% NaOCl, QMiX, 2% chlorhexidine gluconate (CHX), and 17% EDTA. Sterilized saline solution was used as negative control. Survival of bacteria exposed to the irrigants in the presence or absence of dentin was monitored under planktonic conditions. Colony-forming units were counted, and log-transformed numbers were analyzed by using Kruskal-Wallis and Mann-Whitney tests. P values less than .05 were considered significant. Results In the absence of dentin, after 10 seconds of contact with the bacterial suspension, 6% NaOCl showed the lowest bacterial count; the difference to the negative control was significant. After 30 seconds, 6% NaOCl displayed 0 colony-forming units per milliliter, whereas 1% NaOCl and QMiX showed reduced number of colonies in comparison with the negative control. After 1 minute, both concentrations of NaOCl presented no bacterial growth and QMiX reduced the number of colonies, but EDTA and CHX had bacterial counts similar to the negative control. Dentin had a significant inhibitory effect on 6% NaOCl (10 seconds), 1% NaOCl (10 seconds and 1 minute), and QMiX (10 seconds and 1 minute). After 6 hours, both concentrations of NaOCl, QMiX, and CHX killed all bacteria, regardless of the presence of dentin. Conclusions Six percent NaOCl was the most effective irrigant against E. faecalis . Saline and EDTA had no measurable antibacterial effect. Dentin delayed the antibacterial activity of NaOCl and QMiX but did not completely prevent their action.