Disinfection of Contaminated Canals by Different Laser Wavelengths, while Performing Root Canal Therapy

Mohammad Asnaashari--- School of Dentistry, Shahid Beheshti University of Medical Sciences, Tehran, Iran,
Nassimeh Safavi--- Laser Application in Medical Sciences Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran



Removal of smear layer and disinfection of canals are important objectives of teeth root canal cleaning. In order to achieve this purpose, rinsing substances, intra canal drugs as well as ultrasound are used. Today, use of laser to remove smear layer and to disinfect root canals has increasingly attracted the attentions. Till now different lasers such as CO2, Nd:YAG, Er:YAG, Er,Cr:YSGG have been used for debris and smear removal from the canals. Numerous studies have shown that Er:YAG is the most appropriate laser for intra canal debris and smear removal. In addition different laser wavelengths have been used directly or as an adjunctive to disinfect canals. Laser light can penetrate areas of canals where irrigating and disinfecting solutions cannot reach, like secondary canals and deep dentinal tubules and also can eliminate microorganisms. Different studies have confirmed the penetration of Nd:YAG laser in deep dentin and reduction of microorganisms penetration. But studies on comparison of antibacterial effects of Nd:YAG laser with sodium hypochlorite showed effectiveness of both, with a better effect for sodium hypochlorite. Studies performed in relation with anti-microbial effects of Diode laser with various parameters show that this laser can be effective in reducing intra canal bacterial count and penetration in the depth of 500 microns in dentin. In studies performed on Diode laser in combination with canal irrigating solutions such as sodium hypochlorite and oxygenated water better results were obtained. Although studies on disinfection by the Erbium laser family show that use of this laser alone can be effective in disinfecting canals, studies evaluating the disinfecting effects of this laser and different concentrations of sodium hypochlorite show that the latter alone is more effective in disinfecting canals. And better results were obtained when Erbium laser was used in combination with sodium hypochlorite irrigating solution in canals. Results of the aforementioned articles indicate that this laser is effective in combination with a rinsing solution such as sodium hypochlorite.

Results from studies including several types of the different Er:YAG, Ho:YAG, Nd:YAG, Er,Cr:YSGG lasers in disinfecting canals showed that all wavelengths used in disinfection for different thicknesses of dentin were efficacious without damaging thermal effect. Considering that use of different lasers in canals can be accompanied with temperature increase which can sometimes lead to damages to teeth and surrounding tissues, thus the use of photochemical phenomenon for elimination of microorganisms have attracted attention of many researchers. Studies in this field imply the efficacy of this method in reducing canal bacterial count and recommend its use as an adjunctive after biomechanical preparation of canals. Results from performed studies show removal of intra canal debris and smear layer by different lasers and particularly the Erbium laser family. Furthermore various laser wavelengths, particularly of Diode and Nd:YAG lasers can be effective in reducing intra canal microbial count. Maximum effect is obtained when laser light is used in canals in combination with sodium hypochlorite irrigating substance in appropriate concentration. Therefore use of laser energy can improve success rate of root canal treatments.


root canal therapies; Nd:YAG; diode laser

Full Text:




Trope M. The vital tooth: its importance in the study and practice of endodontics. Endodon Topics 2003; 5(1):1.

Chugal NM, Clive JM, Spangberg LS. Endodontic infection: some biologic and treatment factors associated with outcome. Oral Surg Oral Med Oral Path Oral Radiol Endod 2003; 96:81-90.

Friedman S, Mor C. The success of endodontic therapy, healing and functionality. J Calif Dent Assoc 2004; 32:493-503.

Friedman S. Treatment outcome and prognosis of endodontic therapy. In Orstavik D, Pitt-Ford TR, editors: Essential Endodontology. Prevention and Treatment of Apical Periodontitis, London, 1998, Blackwell Science Ltd, p 367.

Waltimo TM, Orstavik D, Siren EK, Haapasalo MP. In vitro yeast infection of human dentin. J Endod 2000;26:207-9.

Ruddle C. Cleaning and shaping the root canal system. In Cohen S, Burns RC, editors. Pathways of the Pulp, ed 8, St Louis, 2002, Mosby.

Hulsmann M, Heckendorff M, Lennon A. Chelating agents in root canal treatment:› mode of action and indications for their use. Int Endod J 2003; 36:810-30.

Love RM, McMillan MD, Park Y, Jenkinson HF. Coinvasion of dentinal tubules by Porphyromonas gingivalis and Streptococcus gordonii depends upon binding specificity of streptococcal antigen I/II adhesion. Infect Immun 2000;68:1359-65.

Love RM, McMillan MD, Jenkinson HF. Invasion of dentinal tubules by oral Streptococci is associated with collagen recognition mediated by the antigen I/U family of polypeptides. Infect Immun 1997;65:5157-64.

Sundqvist G, Figdor D. Endodontic treatment of apical periodontitis. In Orstavik D, Pitt Ford TR, editors. Essential Endodontology, Oxford, England, 1998, Blackwell, p 242.

Fouad AF, Zerella J, Barry J, Spangberg LS. Molecular detection of Enterococcus species in root canals of therapy-resistant endodontic infections. Oral Surg OralMed Oral Pathol Oral Radiol Endod 2005; 99:112-8.

Figdor D, Davies JK, Sundqvist G. Starvation survival, growth and recovery of Enterococcus faecalis in human serum. Oral Microbiol Immunol 2003;18: 234-9.

Fabricius L, Dahlen G, Holm SE, Moller AJ. Influence of combinations of oral bacteria on periapical tissues of monkeys. Scand J Dent Res 1982;90:200-6.

Molander A, Reit C, Dahlen G, Kvist T. Microbiological status of root filled teeth with apical periodontitis. Int Endod J 1998;31:1-7.

Goldman LB, Goldman M, Kronman JH, Lin PS. The efficacy of several irrigating solutions for endodontics: a scanning electron microscopic study. Oral Surg OralMed Oral Pathol 1981; 52:197-204.

Bystorm A, Sundqvist G. Bacteriologic evaluation of the efficacy of mechanical root canal instrumentation in endodontic therapy. Scand J Dent Res 1981;89:321-8.

Card SJ, Sigurdsson A, Orstavik D, Trope M. The effectiveness of increased apical enlargement in reducing intracanal bacteria. J Endod 2002; 28:779-83.

Orstavik D, Haapasalo M. Disinfection by endodontic irrigants and dressings of experimentally infected dentinal tubules. Endod Dent Traumatol 1990; 6:142-9.

Torabinejad M, Handysites R, Khademi AA, Bakland LK. Clinical implications of the smear layer in endodontics: A review. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2002; 94:658-66.

Pashley DH. Smear layer: physiological considerations. Oper Dent Suppl 1984;3:13-29.

Torabinejad M, Khademi AA, Babagoli J, Cho Y, Johnson W, Bozhilove K, et al. A new solution for removal of smear layer. J Endod 2003;29: 170-5.

Takeda FH, Harashima T, Eto JN, Kimura Y, Matsumoto K. Effect of Er: YAG laser treatment on the root canal walls of human teeth: an SEM study. Endod Dent Traumatol 1998 Dec; 14(6):270-3.

Mader CL, Baumgartner JC, Peters DD. Scanning electronic microscopic investigation of smear layer on root canal walls. Endod 1984; 10: 477-83.

Delme K, Meire M, De Bruyne M, Nammour S, De Moor R. Cavity preparation using an Er: YAG laser in the adult dentition. Rev Belge Med Dent 2009; 64(2):71- 80.(French).

Stabholz A, Khayat A, Ravanshad SH, McCarthy DW, Neev J, Torabinejad M. Effect of Nd:YAG laser on apical seal of teeth after apicoectomy and retrofill. J Endod 1992; 18:371-5.

Arens DL, Levy GC, Rizoiu IM. A comparison of dentin permeability after bur and laser apicoectomies. Compendium 1993;14:1290-4.

Goya C, Yamazaki R, Tomita Y, Kimura Y, Matsumoto K. Effect of pulsed laser irradiation on smear layer at the apical stop and apical leakage after obturation. Int Endod J 2000;33:266-71.

Wang X, Sun Y, Kimura Y, Ishiyaki NT, Matsumoto K. Effect of diode irradiation on smear layer removal from root canal walls and apical leakage after obturation. Photomed Laser Surg 2005; 23(6):575-81.

Takeda FH, Harishima LA, Kimura Y, Matsumoto K. A comparative study of the removal of smear layer by three endodontic irrigant and two types of laser. Int Endod J 1999;32:32-9.

Karlovic Z, Pezelj-Ribaric S, Miletic I, Jukic S, Grgurevic J, Anic I. Er:YAG laser versus ultrasonic in preparation of root-end cavities. J Endod 2005; 31:821-3.

Harashima T, Takeda FH, Kimura Y, Matsumoto K. Effect of Nd:YAG laser irradiation for removal of intracanal debris and smear layer in extracted human teeth. J Clin Laser Med Surg 1997;15:131-5.

Chen WH. Laser in root canal therapy. J Indiana Dent Assoc 2003;81(4): 20-3.

Altundasar E, Ozcelik B, Cehreli ZC, Matsumoto K. Ultramorphological and histochemical changes after Er;Cr:YSGG laser irradiation and two different irrigation regimes. J Endod 2006;32:465-8.

Shahabi S, Zendedel S. Atomic analysis and hardness measurement of the cavity prepared by laser. Lasers Med Sci. 2010 May;25(3):379-83.

Yamazaki R, Goya C, Yu DG, Kimura Y, Matsumoto K. Effect of Erbium, Chromium: YSGG laser irradiation on root canal walls: A scanning Electron Microscopic and Thermographic Study. J Endod;27(1): 9-12.

Oguntebi BR. Dentin tubule infection and endodontic therapy implications. Int Endod J 1994;27:218-22.

Peters OA, Schonenberger K, Laib A. Effects of four Ni-Ti preparation techniques on root canal geometry assessed by micro computed tomography. Int Endod J 2001;34:221-30.

Moshonov J, Orstavik D, Yamauchi S, Pettiette M, Trope M. Nd:YAG laser irradiation in root canal disinfection. Endod Dent Traumatol. 1995;11(5):220-4.

Moritz A, Gutknecht N, Goharkhay K, Schoop U, Wernisch J, Sperr W. In vitro irradiation of infected root canals with a diode laser: results of microbiologic, infrared spectrometric and stain penetration examinations. Quintessence Int 1997;28:205-9.

Mehl A, Folwaczny M, Haffner C, Hickel R. Bactericidal effects of 2.94μ Er:YAG laser irradiation in dental root canals. J Endod 1999;25:490-3.

Dostalova T, Jelinkova H, Hausova D, Sulc J, Nemeć M, Dusková J, et al. Endodontic treatment with application of Er: YAG laser waveguide radiation disinfection. J Clin Laser Med Surg 2002;20:135-9.

Schoop U, Moritz A, Kluger W, Patruta S, Goharkhay K, Sperr W, et al. The Er: YAG laser in endodontics: results of an in vitro study. Lasers Surg Med 2002;30: 360-4.

Koba K, Kimura Y, Matsumoto K, Takeuchi T, Ikarugi T, Shimisu T. A histopathological study of the effects of pulsed Nd:YAG laser irradiation on infected root canals in dogs, J Endod 1999;25(3):151-4.

Koba K, Kimura Y, Matsumoto K, Watanabe H, Shinoki T, Koji R, et al. Post-operative symptoms and healing after endodontic treatment of infected teeth using pulsed Nd:YAG laser. Endod Dent Traumatol 1999;15(2):68-72.

Klinke T, Klimm W, Gutknecht N. Antibacterial effects of Nd:YAG laser irradiation within root canal dentin. J Clin Laser Med Surg 1997;15(1):29-31.

Moritz A, Jakolitsch S, Goharkhay K, Schoop U, Kluger W, Mallinger R, et al. Morphologic changes correlating to different sensitivities of Escherichia coli and Entrococcus faecalis to Nd:YAG laser irradiation through dentin. Lasers Surg Med 2000;26:250-61.

Piccolomini R, D›Arcangelo C, D›Ercole S, Catamo G, Schiafino G, De Fazio P. Bacteriologic evaluation of the effect of Nd:YAG laser irradiation in experimental infected root canals. J Endod 2002;28(4):276-8.

Flowaczny M, Mehl A, Jordan C, Hickel R. Antibacterial effects of pulsed Nd:YAG laser radiation at different energy settings in root canals. J Endod 2002; 28(1):24-9.

Bergmans L, Moisiadis P, Teughels W, Van Meerbeek B, Quirynen M, Lambrechts P. Bactericidal effect of Nd:YAG laser irradiation on some endodontic pathogens ex vivo. Int Endod J 2006;39:547-57.

Le Goff A, Dautel-Morazin A, Guigand M, Vulcain JM, Bonnaure-Mallet M. An evaluation of the CO2 laser for endodontic disinfection. J Endod 25(2):105-8.

Gutknecht N, Van Gogswaardt D, Conrads G, Apel C, Schubert C, Lampert F. Diode laser radiation and its bactericidal effect in root canal wall dentin. J Clin Laser Med Surg 2000;18(2):57-60.

Kreisler M, Kohnen W, Beck M, Al Haj H, Christoffers AB, Gotz H, et al. Efficacy of NaOCI/H2O2 irrigation and GaAlAs laser in decontamination of root canals in vitro. Lasers Surg Med 2003;32:189-96.

Gutknecht N, Franzen R, Schippers M, Lampert F. Bactericidal effect of a 980- nm diode laser in the root canal wall dentin of bovine teeth. J Clin Laser Med Surg 2004;22(1): 9-13.

De Sauza EB, Cai S, Simionato MR, Lage-Marques JL. High power diode laser in the disinfection in depth of the root canal dentin. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2008; 106(1):e68-72.

Dostalova T, Jelinkova H, Housova D, Sulc J, Nemec M, Duskova J, et al. Endodontic treatment with application of Er: YAG laser waveguide radiation disinfection. J Clin Laser Med Surg 2002; 20(3):135-9.

Perin FM, França SC, Silva-Sousa YT, Alfredo E, Saquy PC, Estrela C, et al. Evaluation of the antimicrobial effect of Er:YAG laser irradiation versus 1% sodium hypochlorite irrigation for root canal disinfection. Aust Endod J 2004;30(1):20-2.

Kangarloo A, Fekrazad R, Salar O. Antibacterial effect of Er,Cr: YSGG laser and 2%chlorhexidine solution on dental tubules infected by E. faecalis. Thesis No:2519- 2004.

Vezzani MS, Pietro R, Silva-Sousa YT, Brugnera-Junior A, Sousa-Neto MD. Disinfection of root canals using Er: YAG laser at different frequencies. Photomed Laser Surg 2006; 24(4):499-502.

Godon W, Atabakhsh VA, Meza F, Doms A, Nissan R, Rizoiu I, et al. The antimicrobial efficacy of the erbium, chromium:yttrium-scandium-gallium-garnet laser with radial emitting tips on root canal dentin walls infected with Enterococcus faecalis. J Am Dent Assoc; 138(7):992-1002.

Eldeniz AU, Ozer F, Hadimli HH, Erganis O. Bactericidal efficacy of Er,Cr: YSGG laser irradiation against Enterococcus faecalis compared with NaOCI irrigation: an ex vivo pilot study. Int Endod J;40(2):112-9.

Schoop U, Goharkhay K, Klimscha J, Zagler M, Wernisch J, Georgopoulos A, et al. The use of the Erbium, Chromium:Yttrium-Scandium-Gallium-Garnet laser in endodontic treatment: the results of an in vitro study. J Am Dent Assoc 2007;138(7):949-55.

Moritz A, Schoop U, Goharkhay K, Jakolitsch S, Kluger W, Wernisch J, et al. The bactericidal effect of Nd:YAG, Ho:YAG, and Er:YAG laser irradiation in the root canal: an in vitro comparison. J Clin Laser Med Surg 1999;17(4):161-4.

Schoop U, Kluger W, Moritz A, Nedjelik N, Georgopoulos A, Sperr W. Bactericidal effect of different laser systems in the deep layers of dentin. Lasers Surg Med 2004;35: 111-6.

Garcez AS, Nunez SC, Hamblin MR, Riberio MS. Antimicrobial effects of photodynamic therapy on patients with necrotic pulps and periapical lesion. J Endod. 2008;34(2):138-42.

Foschi F, Fontana CR, Ruggiero K, Riahi R, Vera A, Doukas AG, et al. Photodynamic inactivation of Enterococcus faecalis in dental root canals in vitro. Lasers Surg Med 2007;39(10):782-7.

Fimple JL, Fontana CR, Foschi F, Ruggiero K, Song X, Pagonis TC, et al. Photodynamic treatment of endodontic polymicrobial infection in vitro. J Endod 2008;34(6):728- 34.

Fonseca MB, Junior PO, Pallota RC, Filho HF, Denardin OV, Rapoport A, et al. Photodynamic therapy for root canals infected with Enterococcus faecalis. Photomed Laser Surg 2008;26(3):209-13.

Meire MA, De Prijck K, Coenye T, Nelis HJ, De Moor RJ. Effectiveness of different laser systems to kill Enterococcus faecalis in aqueous suspension and in an infected tooth model. Int Endod J 2009;42,351-9.

Stabholtz A, Zeltzer R, Sela M, Peretz B, Moshonov J, Ziskind D. The use of lasers in dentistry: principles of operation and clinical applications. Compend Contin Educ Dent 2003;24:935-48.

Asnaashari M, Asnaashari N. Clinical application of 810nm diode laser and low level laser therapy for treating an endodontic problem. J Lasers Med Sci.2011;2(2):82-6

Stabholtz A. The role of laser technology in modern endodontics. In: Ishikawa I, Frame JW, Aoki A,editors. Lasers in dentistry, revolution of dental treatment in the new millennium. Elsevier Science BV Int Congr Series 2003;1284:21-7.

DOI: http://dx.doi.org/10.22037/2010.v4i1.3869

Copyright © 2012 J Lasers Med Sci "Powered by Open Journal Systems"


Site Map | Privacy Statement | About JLMS | Contact | Search| Current | Archives | Open Access

ISSN: 2008-9783/E.ISSN: 2228-6721. Published quarterly by: Laser Application in Medical Sciences Research Center