title: Antibacterial and residual antimicrobial activities against Enterococcus faecalis biofilm: A comparison between EDTA, chlorhexidine, cetrimide, MTAD and QMix.
abstract: We compared the antibacterial and residual antimicrobial activities of five root canal irrigants (17% EDTA,2% chlorhexidine,0.2% cetrimide, MTAD, and QMix) in a model of Enterococcus faecalis biofilm formation. Sixty dentin blocks with 3-week E. faecalis biofilm were divided into six equal groups and flushed with irrigant for 2 min or left untreated. A blank control group was also established. Antibacterial activities of the irrigants were evaluated by counting colony forming units. To test residual antimicrobial activities, 280 dentin blocks were divided into seven equal groups and flushed with irrigant for 2 min or left untreated and then incubated with E. faecalis suspension for 48 h, or used as a blank. No bacteria were observed in the blank control group. The number of viable E. faecalis was significantly fewer in the irrigant-treated groups compared with the untreated control (P < 0.05). Among the five irrigants, QMix had the strongest antibacterial activity. Residual antimicrobial activities of CHX were significantly higher at 12 h, 24 h and 36 h compared to untreated control (P < 0.05). All five root canal irrigants were effective to some extent against E. faecalis, but QMix and CHX had the strongest, and CHX the longest (up to 36 h), antimicrobial activity.
authors.affiliation: Department of Endodontics and Restorative Dentistry, School of Stomatology, Tianjin Medical University, Tianjin, China.
authors.forename: Rui
authors.initials: R
authors.lastname: Zhang
authors.affiliation: Department of Endodontics and Restorative Dentistry, School of Stomatology, Tianjin Medical University, Tianjin, China.
authors.forename: Min
authors.initials: M
authors.lastname: Chen
authors.affiliation: Department of Endodontics and Restorative Dentistry, School of Stomatology, Tianjin Medical University, Tianjin, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Lu
authors.affiliation: Department of Endodontics and Restorative Dentistry, School of Stomatology, Tianjin Medical University, Tianjin, China.
authors.forename: Xiangjun
authors.initials: X
authors.lastname: Guo
authors.affiliation: Department of Maxillofacial Surgery, School of Stomatology, Tianjin Medical University, Tianjin, China.
authors.forename: Feng
authors.initials: F
authors.lastname: Qiao
authors.affiliation: Department of Endodontics and Restorative Dentistry, School of Stomatology, Tianjin Medical University, Tianjin, China.
authors.forename: Ligeng
authors.initials: L
authors.lastname: Wu
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D018441:Biofilms / Q000187:drug effects* / Q000254:growth & development; D000077286:Cetrimonium; D002593:Cetrimonium Compounds / Q000494:pharmacology*; D002710:Chlorhexidine / Q000494:pharmacology*; D004492:Edetic Acid / Q000494:pharmacology*; D013293:Enterococcus faecalis / Q000502:physiology*
chemical_list: D000900:Anti-Bacterial Agents; D002593:Cetrimonium Compounds; D004492:Edetic Acid; D002710:Chlorhexidine; D000077286:Cetrimonium