Abstract
Endodontic restorations often fail due to inadequate disinfection of the root canal even though the antimicrobial irrigants used have been shown to be capable of killing the bacterium frequently implicated in this complication, Enterococcus faecalis (Ef). Extracted human teeth were root-prepared and filled with a liquid culture of Ef. Following incubation, the root canals were irrigated with 1% sodium hypochlorite (NaOCl), electrochemically activated water or saline control. Irrigation was modelled using an electronic pipette to deliver the solutions at a reproducible flow velocity. A series of parallel experiments employed a membrane biofilm model that was directly immersed into irrigant. Experimental conditions where contiguous between the extracted tooth model and biofilm model wherever possible. After 60 s of exposure, 1% NaOCl effectively sterilised the biofilm model, whereas log 3.36 viable Ef where recoverable from the analogous extracted tooth model, the other irrigants proved ineffective. Biofilms of Ef were susceptible to concentrations of irrigant that proved ineffective in the tooth model. NaOCl was the most effective biocide in either case. This suggests that the biofilm modality of bacterial growth may not be the most important factor for the recalcitrance of root canal infections during endodontic irrigation; it is more likely due to the inability of the irrigant to access the infection.
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References
Bergstedt MS, Hondzo MM, Cotner JB (2004) Effects of small scale fluid motion on bacterial growth and respiration. Freshw Biol 49:28–40
Ciucchi B, Bouillaguet S, Holz J, Pashley D (1995) Dentinal fluid dynamics in human teeth, in vivo. J Endod 21:191–194
Cunningham WT, Cole JS III, Balekjian AY (1982) Effect of alcohol on the spreading ability of sodium hypochlorite endodontic irrigant. Oral Surg Oral Med Oral Pathol 54:333–335
Dammaschke T, Witt M, Ott K, Schafer E (2004) Scanning electron microscopic investigation of incidence, location, and size of accessory foramina in primary and permanent molars. Quintessence Int 35:699–705
Davis JM, Maki J, Bahcall JK (2007) An in vitro comparison of the antimicrobial effects of various endodontic medicaments on Enterococcus faecalis. J Endod 33:567–569
Duggan JM, Sedgley CM (2007) Biofilm formation of oral and endodontic enterococcus faecalis. J Endod 33:815–818
Dunavant TR, Regan JD, Glickman GN, Solomon ES, Honeyman AL (2006) Comparative evaluation of endodontic irrigants against Enterococcus faecalis biofilms. J Endod 32:527–531
el-Falaha BM, Furr JR, Russell AD (1987) Quenching of the antibacterial activity of chlorhexidine and benzalkonium by Letheen broth and Letheen agar in relation to wild-type and envelope mutant strains of gram-negative bacteria. Microbios 49:31–37
Fabricius L, Dahlen G, Holm SE, Moller AJ (1982) Influence of combinations of oral bacteria on periapical tissues of monkeys. Scand J Dent Res 90:200–206
Gilbert P, Maira-Litran T, McBain AJ, Rickard AH, Whyte FW (2002) The physiology and collective recalcitrance of microbial biofilm communities. Adv Microb Physiol 46:202–256
Gulabivala K, Stock CJ, Lewsey JD, Ghori S, Ng YL, Spratt DA (2004) Effectiveness of electrochemically activated water as an irrigant in an infected tooth model. Int Endod J 37:624–631
Jannasch HW, Jones GE (1959) Bacterial populations in sea water as determined by different methods of enumeration. Limnol Oceanogr 4:128–139
Kaufman AY, Keila S (1989) Hypersensitivity to sodium hypochlorite. J Endod 15:224–226
Kokkinosa A, Fasseas C, Eliopoulos E, Kalantzopoulos G (1998) Cell size of various lactic acid bacteria as determined by scanning electron microscope and image analysis. Lait 78:491–500
Laplace JM, Thuault M, Hartke A, Boutibonnes P, Auffray Y (1997) Sodium hypochlorite stress in Enterococcus faecalis: influence of antecedent growth conditions and induced proteins. Curr Microbiol 34:284–289
Lima KC, Fava LR, Siqueira JF Jr (2001) Susceptibilities of Enterococcus faecalis biofilms to some antimicrobial medications. J Endod 27:616–619
Martin MV, Gallagher MA (2005) An investigation of the efficacy of super-oxidised (Optident/Sterilox) water for the disinfection of dental unit water lines. Br Dent J 198:353–354
Molander A, Reit C, Dahlen G, Kvist T (1998) Microbiological status of root-filled teeth with apical periodontitis. Int Endod J 31:1–7
Pratten J, Wilson M (1999) Antimicrobial susceptibility and composition of microcosm dental plaques supplemented with sucrose. Antimicrob Agents Chemother 43:1595–1599
Radcliffe CE et al (2004) Antimicrobial activity of varying concentrations of sodium hypochlorite on the endodontic microorganisms Actinomyces israelii, A. naeslundii, Candida albicans and Enterococcus faecalis. Int Endod J 37:438–446
Schiott CR, Loe H, Jensen SB, Kilian M, Davies RM, Glavind K (1970) The effect of chlorhexidine mouthrinses on the human oral flora. J Periodontal Res 5:84–89
Sena NT et al (2006) In vitro antimicrobial activity of sodium hypochlorite and chlorhexidine against selected single-species biofilms. Int Endod J 39:878–885
Siqueira JF Jr, Rocas IN, Favieri A, Lima KC (2000) Chemomechanical reduction of the bacterial population in the root canal after instrumentation and irrigation with 1%, 2.5%, and 5.25% sodium hypochlorite. J Endod 26:331–334
Siqueira JF Jr, Paiva SS, Rocas IN (2007) Reduction in the cultivable bacterial populations in infected root canals by a chlorhexidine-based antimicrobial protocol. J Endod 33:541–547
Sjogren U, Figdor D, Persson S, Sundqvist G (1997) Influence of infection at the time of root filling on the outcome of endodontic treatment of teeth with apical periodontitis. Int Endod J 30:297–306
Spratt DA, Pratten J, Wilson M, Gulabivala K (2001) An in vitro evaluation of the antimicrobial efficacy of irrigants on biofilms of root canal isolates. Int Endod J 34:300–307
Walker A (1936) A definitive and dependable therapy for pulpless teeth. J Am Dent Assoc 23:1418–1424
Acknowledgments
The extracted tooth model experiments, by SGG, were funded by the School of Dental Sciences, University of Liverpool, as a 4th year undergraduate Bachelor of Dental Sciences elective project, whilst the filter-membrane biofilm models were undertaken as part of a self-funded post-graduate degree by QW who is in turn partly supported by a University of Liverpool Graduates Association (Hong Kong) Scholarship. The authors would like to thank Dr Fadi Jarad BDS PhD MDFS RCS (Eng) for editorial comments. CKH wishes to highlight the work of the late Professor Peter Gilbert (1951–2008) as an inspiration to those involved in modelling microbial biofilms.
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Communicated by Jorge Membrillo-Hernández.
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Hope, C.K., Garton, S.G., Wang, Q. et al. A direct comparison between extracted tooth and filter-membrane biofilm models of endodontic irrigation using Enterococcus faecalis . Arch Microbiol 192, 775–781 (2010). https://doi.org/10.1007/s00203-010-0604-6
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DOI: https://doi.org/10.1007/s00203-010-0604-6