Abstract
Introduction
This in vitro study aimed to investigate the antibacterial effects of photodynamic therapy (PDT)
with methylene blue (MB) or toluidine blue (TB) (both at 15 μg/mL) as a supplement
to instrumentation/irrigation of root canals experimentally contaminated with Enterococcus faecalis.
Methods
Seventy extracted teeth had their root canals contaminated with an endodontic strain
of E. faecalis for 7 days, instrumented with nickel-titanium instruments and irrigated either with
2.5% NaOCl or with 0.85% NaCl, and then randomly distributed into four experimental
groups: MB/NaOCl (PDT with MB and NaOCl as the irrigant), TB/NaOCl (PDT with TB and
NaOCl as the irrigant), MB/NaCl (PDT with MB and NaCl as the irrigant), and TB/NaCl
(PDT with TB and NaCl as the irrigant). For PDT, the photosensitizer remained in the
canal for 2 minutes before exposed to red light emitted from a diode laser for 4 minutes.
Samples were taken before and after instrumentation/irrigation and following the specific
PDT procedure for each group, plated onto Mitis-salivarius agar and the colony forming
units counted.
Results
Regardless of the irrigant used (NaOCl or NaCl), instrumentation significantly reduced
bacterial counts in comparison to the baseline (p < 0.001). NaOCl as the irrigant
was significantly more effective than NaCl, and this difference persisted after PDT,
irrespective of the photosensitizer used (p < 0.05). PDT with either MB or TB did
not significantly enhance disinfection after chemomechanical preparation using NaOCl
as irrigant (p > 0.05). No significant differences were observed between the two photosensitizers
(p > 0.05).
Conclusion
These in vitro results suggest that PDT with either MB or TB may not exert a significant supplemental
effect to instrumentation/irrigation procedures with regard to intracanal disinfection.
Further adjustments in the PDT protocol may be required to enhance predictability
in bacterial elimination before clinical use is recommended.
Key Words
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References
- Clinical implications and microbiology of bacterial persistence after treatment procedures.J Endod. 2008; 34: 1291-1301
- Reduction of intracanal bacteria using GT rotary instrumentation, 5.25% NaOCl, EDTA, and Ca(OH)2.J Endod. 2005; 31: 359-363
- The antibacterial action of sodium hypochlorite and EDTA in 60 cases of endodontic therapy.Int Endod J. 1985; 18: 35-40
- Reduction of intracanal bacteria using nickel-titanium rotary instrumentation and various medications.J Endod. 2000; 26: 751-755
- Influence of infection at the time of root filling on the outcome of endodontic treatment of teeth with apical periodontitis.Int Endod J. 1997; 30: 297-306
- Microbiological evaluation of one- and two-visit endodontic treatment of teeth with apical periodontitis: a randomized, clinical trial.J Endod. 2004; 30: 572-576
- Bacteriologic investigation of the effects of sodium hypochlorite and chlorhexidine during the endodontic treatment of teeth with apical periodontitis.Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2007; 104: 122-130
- The antimicrobial effect of calcium hydroxide as a short-term intracanal dressing.Int Endod J. 1991; 24: 119-125
- Bacterial reduction in infected root canals treated with 2.5% NaOCl as an irrigant and calcium hydroxide/camphorated paramonochlorophenol paste as an intracanal dressing.J Endod. 2007; 33: 667-672
- Reduction in the cultivable bacterial populations in infected root canals by a chlorhexidine-based antimicrobial protocol.J Endod. 2007; 33: 541-547
- One-appointment endodontic therapy: biological considerations.J Am Dent Assoc. 2007; 138: 1456-1462
- Antibacterial efficacy of calcium hydroxide intracanal dressing: a systematic review and meta-analysis.Int Endod J. 2007; 40: 2-10
- Photodynamic therapy in dentistry.J Dent Res. 2007; 86: 694-707
- Photodynamic therapy for root canals infected with Enterococcus faecalis.Photomed Laser Surg. 2008; 26: 209-213
- Efficiency of NaOCl and laser-assisted photosensitization on the reduction of Enterococcus faecalis in vitro.Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2006; 102: e93-e98
- Antimicrobial photodynamic therapy combined with conventional endodontic treatment to eliminate root canal biofilm infection.Lasers Surg Med. 2007; 39: 59-66
- Photodynamic therapy for endodontic disinfection.J Endod. 2006; 32: 979-984
- Antibacterial action of photoactivated disinfection (PAD) used on endodontic bacteria in planktonic suspension and in artificial and human root canals.J Dent. 2006; 34: 363-371
- Effect of photo-activated disinfection on endodontic pathogens ex vivo.Int Endod J. 2008; 41: 227-239
- Photodynamic treatment of endodontic polymicrobial infection in vitro.J Endod. 2008; 34: 728-734
- Effectiveness of different laser systems to kill Enterococcus faecalis in aqueous suspension and in an infected tooth model.Int Endod J. 2009; 42: 351-359
- Light activated disinfection: an alternative endodontic disinfection strategy.Aust Dent J. 2009; 54: 108-114
- Antimicrobial effects of photodynamic therapy on patients with necrotic pulps and periapical lesion.J Endod. 2008; 34: 138-142
- Microbiological evaluation of photo-activated disinfection in endodontics (an in vivo study).Br Dent J. 2006; 200 (discussion 29): 337-341
- Identification of Enterococcus faecalis in root-filled teeth with or without periradicular lesions by culture-dependent and -independent approaches.J Endod. 2006; 32: 722-726
- Enterococcus faecalis: its role in root canal treatment failure and current concepts in retreatment.J Endod. 2006; 32: 93-98
- Enterococcus spp. in endodontically treated teeth with and without periradicular lesions.J Endod. 2005; 31: 851-856
- Enterococcus faecalis—a mechanism for its role in endodontic failure.Int Endod J. 2001; 34: 399-405
- Survival of Enterococcus faecalis in root canals ex vivo.Int Endod J. 2005; 38: 735-742
- The role of environmental changes on monospecies biofilm formation on root canal wall by Enterococcus faecalis.J Endod. 2005; 31: 867-872
- Photodynamic inactivation of Enterococcus faecalis in dental root canals in vitro.Lasers Surg Med. 2007; 39: 782-787
- Augmenting the antibiofilm efficacy of advanced noninvasive light activated disinfection with emulsified oxidizer and oxygen carrier.J Endod. 2008; 34: 1119-1123
- Photodynamic therapy targeted to pathogens.Int J Immunopathol Pharmacol. 2004; 17: 245-254
- Mechanisms in photodynamic therapy: part one—photosensitizers, photochemistry and cellular localization.Photodiagnosis Photodyn Ther. 2004; 1: 279-293
- The development of phenothiazinium photosensitisers.Photodiagnosis Photodyn Ther. 2005; 2: 263-272
- An in vitro comparison of the bactericidal efficacy of lethal photosensitization or sodium hyphochlorite irrigation on Streptococcus intermedius biofilms in root canals.Int Endod J. 2002; 35: 268-274
Article info
Publication history
Published online: December 07, 2009
Footnotes
Supported in part by grants from Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq), and Fundação Carlos Chagas Filho de Amparo à Pesquisa do Estado do Rio de Janeiro (FAPERJ), Brazilian Governmental Institutions
Identification
Copyright
© 2010 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.
