- •We formed biofilms in teeth with large root canals and unlimited irrigant access.
- •The effect of mechanical instrumentation (MI) and noninvasive irrigating protocols on bacteria was compared.
- •MI was the most effective and reliable method to disinfect large root canals.
- •Passive ultrasonic irrigation (PUI) enhanced the efficacy of sodium hypochlorite irrigation.
- •Noninvasive disinfection protocols, including PUI, could not substitute for MI.
This study compared the effectiveness of different disinfection protocols in reducing bacteria in an Enterococcus faecalis biofilm in teeth with large root canals.
Fifty-five roots were prepared from human mandibular premolars with large single root canals, and 50 roots were infected with E. faecalis for 21 days. Four roots were observed using scanning electron microscopy to verify biofilm formation. The remaining specimens were assigned into 5 experimental groups and a sterile control group: mechanical instrumentation using files size 60–90 and 2.5% sodium hypochlorite (NaOCl) (MI-N), irrigation with 2.5% NaOCl (IR-N), irrigation with 2.5% NaOCl using intermittent passive ultrasonic irrigation (PUI-N), irrigation with normal saline, and no intervention (initial). After root canal disinfection, dentin specimens were collected for microbial analysis. Mean colony forming units were determined and compared between groups using 1-way analysis of variance.
The lowest number of intracanal bacteria (24.5 colony-forming units/mL) was recovered from the MI-N group followed by the PUI-N and IR-N groups. The irrigation with normal saline group did not show a significant reduction compared with the initial group. However, there were significant differences between groups (P < .01). The remaining bacteria in the PUI-N group was 4.5-fold lower compared with the IR-N group; however, it was 1862-fold higher compared with the MI-N group.
MI-N was the most effective method to disinfect large root canals. Although ultrasonic activation enhanced the efficacy of root canal irrigation, it could not substitute for mechanical instrumentation even in large root canals with unlimited irrigant access to the apical portion.
To read this article in full you will need to make a payment
Purchase one-time access:Academic & Personal: 24 hour online accessCorporate R&D Professionals: 24 hour online access
One-time access price info
- For academic or personal research use, select 'Academic and Personal'
- For corporate R&D use, select 'Corporate R&D Professionals'
Subscribe:Subscribe to Journal of Endodontics
Already a print subscriber? Claim online access
Already an online subscriber? Sign in
Register: Create an account
Institutional Access: Sign in to ScienceDirect
- Persistent, recurrent, and acquired infection of the root canal system post-treatment.Endod Topics. 2003; 6: 29-56
- Histologic investigation of root canal-treated teeth with apical periodontitis: a retrospective study from twenty-four patients.J Endod. 2009; 35: 493-502
- Antibiotic resistance and capacity for biofilm formation of different bacteria isolated from endodontic infections associated with root-filled teeth.J Endod. 2014; 40: 223-230
- Biofilms in endodontic infections.Endod Topics. 2004; 9: 27-36
- Bacterial reduction with nickel-titanium rotary instrumentation.J Endod. 1998; 24: 763-767
- Reduction of intracanal bacteria using nickel-titanium rotary instrumentation and various medications.J Endod. 2000; 26: 751-755
- The principles of techniques for cleaning root canals.Aust Dent J. 2007; 52: S52-S63
- Root canal irrigants.J Conserv Dent. 2010; 13: 256-264
- Penetration of sodium hypochlorite into dentin.J Endod. 2010; 36: 793-796
- The effectiveness of passive ultrasonic irrigation on intraradicular Enterococcus faecalis biofilms in extracted single-rooted human teeth.Int Endod J. 2010; 43: 241-250
American Association of Endodontists. AAE clinical considerations for a regenerative procedure. Available at: http://www.aae.org/uploadedfiles/publications_and_research/research/currentregenerativeendodonticconsiderations.pdf. Accessed December 7, 2015.
- Translational science in disinfection for regenerative endodontics.J Endod. 2014; 40: S52-S57
- Revascularization of immature permanent teeth with apical periodontitis: new treatment protocol?.J Endod. 2004; 30: 196-200
- Revascularization of an immature permanent tooth with apical periodontitis and sinus tract.Dent Traumatol. 2001; 17: 185-187
- Histologic and immunohistochemical findings of a human immature permanent tooth with apical periodontitis after regenerative endodontic treatment.J Endod. 2015; 41: 1172-1179
- Pulp revascularization on permanent teeth with open apices in a middle-aged patient.J Endod. 2015; 41: 1571-1575
- Microbial evaluation of traumatized teeth treated with triple antibiotic paste or calcium hydroxide with 2% chlorhexidine gel in pulp revascularization.J Endod. 2014; 40: 778-783
- The effect of ultrasonically activated irrigation on reduction of Enterococcus faecalis in experimentally infected root canals.Int Endod J. 2010; 43: 968-977
- Passive ultrasonic irrigation of the root canal: a review of the literature.Int Endod J. 2007; 40: 415-426
- A comparison of canal preparations in straight and curved root canals.Oral Surg Oral Med Oral Pathol. 1971; 32: 271-275
- Study on the influence of refreshment/activation cycles and irrigants on mechanical cleaning efficiency during ultrasonic activation of the irrigant.J Endod. 2010; 36: 737-740
- Bacteria recovered from teeth with apical periodontitis after antimicrobial endodontic treatment.Int Endod J. 2003; 36: 500-508
- Biofilm formation in medicated root canals.J Endod. 2002; 28: 689-693
- The role of environmental changes on monospecies biofilm formation on root canal wall by Enterococcus faecalis.J Endod. 2005; 31: 867-872
- Irrigation in endodontics.Br Dent J. 2014; 216: 299-303
- Bacteriologic evaluation of the efficacy of mechanical root canal instrumentation in endodontic therapy.Scand J Dent Res. 1981; 89: 321-328
- The effect of exposure to irrigant solutions on apical dentin biofilms in vitro.J Endod. 2006; 32: 434-437
- Concentration-dependent effect of sodium hypochlorite on stem cells of apical papilla survival and differentiation.J Endod. 2014; 40: 51-55
- Endosonics—the ultrasonic synergistic system of endodontics.Endod Dent Traumatol. 1985; 1: 201-206
- The influence of volume, type of irrigant and flushing method on removing artificially placed dentine debris from the apical root canal during passive ultrasonic irrigation.Int Endod J. 2006; 39: 472-476
- Effect of ultrasonics on Enterococcus faecalis biofilm in a bovine tooth model.J Endod. 2011; 37: 1128-1133
- Recommendations for using regenerative endodontic procedures in permanent immature traumatized teeth.Dent Traumatol. 2012; 28: 33-41
- The relationship of root canal enlargement to finger-spreader induced vertical root fracture.J Endod. 1997; 23: 533-534
- Fracture resistance of retreated roots using different retreatment systems.Eur J Dent. 2011; 5: 387-392
- Resistance to fracture of endodontically treated roots.Oral Surg Oral Med Oral Pathol. 1992; 73: 99-102
Published online: January 29, 2016
© 2016 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.