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Thermal Changes in Root Surface of Primary Teeth During Root Canal Treatment With Diode Lasers: An In Vitro Study

Bahman Seraj, Zahra Moosavi Garmaroodi, Nasim Chiniforush, Sara Ghadimi




Introduction: Increased temperature due to the application of laser during root canal disinfection may damage periodontium, alveolar bone, and permanent dental germ. The aim of this study was to evaluate the temperature increase of the external surface of primary roots due to the application of 810 nm and 980 nm diode lasers.
Methods: A total of 58 extracted human primary teeth were prepared and randomly divided into two groups: (a) 810 nm diode laser and (b) 980 nm diode laser. Then, each group was divided into 4 subgroups based on the location of the temperature measurement, including subgroup 1: external root surface of primary anterior roots (A); subgroup 2: external root surface of posterior teeth at inter-root space (IS); subgroup 3: external root surface of posterior teeth at outer-root space (OS) and subgroup 4: external surface of furcation area of posterior teeth (F).
Results: The mean temperature rise in group a (7.02±2.95ºC) was less than that of group b (10.62±4.59ºC) (P < 0.001). Also, a significant difference was found between the laser groups in terms of the mean temperature rise of the external root surface at IS, OS and F, with higher temperature increase occurring in all points in laser b. The comparison of irradiation points in each laser showed a higher mean temperature rise for IS than OS, but this difference was only significant in group b (P < 0.001).
Conclusion: Within the studied parameters, 810 nm and 980 nm diode lasers should be used cautiously in primary root canals because of their temperature rise during their application.


Diode laser; temperature rise;primary teeth


Siqueira JF Jr. Aetiology of root canal treatment failure: why well-treated teeth can fail. Int Endod J. 2001;34(1):1-10.

Wang QQ, Zhang CF, Yin XZ. Evaluation of the bactericidal effect of Er,Cr:YSGG, and Nd:YAG lasers in experimentally infected root canals. J Endod. 2007;33(7):830-832. doi:10.1016/j.joen.2007.03.017

Dickers B, Lamard L, Peremans A, et al. Temperature rise during photo-activated disinfection of root canals. Lasers Med Sci. 2009;24(1):81-85. doi:10.1007/s10103-007-0526-y

Bago I, Plecko V, Gabric Panduric D, Schauperl Z, Baraba A, Anic I. Antimicrobial efficacy of a high-power diode laser, photo-activated disinfection, conventional and sonic activated irrigation during root canal treatment. Int Endod J. 2013;46(4):339-347. doi:10.1111/j.1365-2591.2012.02120.x

Friedman S, Abitbol S, Lawrence HP. Treatment outcome in endodontics: the Toronto Study. Phase 1: initial treatment. J Endod. 2003;29(12):787-793. doi:10.1097/00004770- 200312000-00001

Beer F, Buchmair A, Wernisch J, Georgopoulos A, Moritz A. Comparison of two diode lasers on bactericidity in root canals--an in vitro study. Lasers Med Sci. 2012;27(2):361- 364. doi:10.1007/s10103-011-0884-3

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(2):111- 116. doi:10.1002/lsm.20026

Alfredo E, Marchesan MA, Sousa-Neto MD, Brugnera- Junior A, Silva-Sousa YT. Temperature variation at the external root surface during 980-nm diode laser irradiation in the root canal. J Dent. 2008;36(7):529-534. doi:10.1016/j. jdent.2008.03.009

Bystrom A, Sundqvist G. Bacteriologic evaluation of the efficacy of mechanical root canal instrumentation in endodontic therapy. Scand J Dent Res. 1981;89(4):321-328.

Franzen R, Gutknecht N, Falken S, Heussen N, Meister J. Bactericidal effect of a Nd:YAG laser on Enterococcus faecalis at pulse durations of 15 and 25 ms in dentine depths of 500 and 1,000 mum. Lasers Med Sci. 2011;26(1):95-101. doi:10.1007/s10103-010-0826-5

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. doi:10.1089/clm.2000.18.57

Kreisler M, Kohnen W, Beck M, et al. Efficacy of NaOCl/ H2O2 irrigation and GaAlAs laser in decontamination of root canals in vitro. Lasers Surg Med. 2003;32(3):189-196. doi:10.1002/lsm.10148

Schoop U, Kluger W, Dervisbegovic S, et al. Innovative wavelengths in endodontic treatment. Lasers Surg Med. 2006;38(6):624-630. doi:10.1002/lsm.20331

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(7):547-557. doi:10.1111/j.1365- 2591.2006.01115.x

de Souza 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. doi:10.1016/j. tripleo.2008.02.032

Kaiwar A, Usha HL, Meena N, Ashwini P, Murthy CS. The efficiency of root canal disinfection using a diode laser: in vitro study. Indian J Dent Res. 2013;24(1):14-18. doi:10.4103/0970-9290.114916

da Costa Ribeiro A, Nogueira GE, Antoniazzi JH, Moritz A, Zezell DM. Effects of diode laser (810 nm) irradiation on root canal walls: thermographic and morphological studies. J Endod. 2007;33(3):252-255. doi:10.1016/j. joen.2006.09.002

He H, Yu J, Song Y, Lu S, Liu H, Liu L. Thermal and morphological effects of the pulsed Nd:YAG laser on root canal surfaces. Photomed Laser Surg. 2009;27(2):235-240. doi:10.1089/pho.2008.2244

Gutknecht N, Franzen R, Meister J, Vanweersch L, Mir M. Temperature evolution on human teeth root surface after diode laser assisted endodontic treatment. Lasers Med Sci. 2005;20(2):99-103. doi:10.1007/s10103-005-0347-9

Hmud R, Kahler WA, Walsh LJ. Temperature changes accompanying near infrared diode laser endodontic treatment of wet canals. J Endod. 2010;36(5):908-911. doi:10.1016/j.joen.2010.01.007

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. doi:10.1089/ clm.1997.15.29

Strakas D, Franzen R, Kallis A, Vanweersch L, Gutknecht N. A comparative study of temperature elevation on human teeth root surfaces during Nd:YAG laser irradiation in root canals. Lasers Med Sci. 2013;28(6):1441-1444. doi:10.1007/ s10103-012-1203-3

Fransson H, Larsson KM, Wolf E. Efficacy of lasers as an adjunct to chemo-mechanical disinfection of infected root canals: a systematic review. Int Endod J. 2013;46(4):296- 307. doi:10.1111/iej.12003

Abad-Gallegos M, Arnabat-Dominguez J, Espana-Tost A, Berini-Aytes L, Gay-Escoda C. In vitro evaluation of the temperature increment at the external root surface after Er,Cr:YSGG laser irradiation of the root canal. Med Oral Patol Oral Cir Bucal. 2009;14(12):e658-662.

Nammour S, Kowaly K, Powell GL, Van Reck J, Rocca JP. External temperature during KTP-Nd:YAG laser irradiation in root canals: an in vitro study. Lasers Med Sci. 2004;19(1):27-32. doi:10.1007/s10103-004-0303-0

Sauk JJ, Norris K, Foster R, Moehring J, Somerman MJ. Expression of heat stress proteins by human periodontal ligament cells. J Oral Pathol. 1988;17(9-10):496-499.

Eriksson AR, Albrektsson T. Temperature threshold levels for heat-induced bone tissue injury: a vital-microscopic study in the rabbit. J Prosthet Dent. 1983;50(1):101-107.

Gutknecht N. Lasers in endodontics. J Laser Health Acad. 2008;4:1-4.

Nammour S, Rocca JP, Keiani K, et al. Pulpal and periodontal temperature rise during KTP laser use as a root planing complement in vitro. Photomed Laser Surg. 2005;23(1):10-14. doi:10.1089/pho.2005.23.10

DOI: https://doi.org/10.22037/jlms.v9i4.17561