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Application of Low level Lasers in Dentistry (Endodontic)

Mohammad Asnaashari, Nassimeh Safavi




Low level lasers, cold or soft lasers:

These lasers do not produce thermal effects on tissues and induce photoreactions in cellsthrough light stimulation which is called photobiostimulation. Power of these lasers is usually under 250mW.

The main point differentiating low level lasers and high power ones is the activation of photochemical reactions without heat formation. The most important factor to achieve this light characteristic in lasers is not their power, but their power density for each surface unit (i.e cm2). Density lower than 670mW/cm2, can induce the stimulatory effects of low level lasers without thermal effects.

Low level lasers (therapeutic) used today as treatment adjunctive devices in medicine and dentistry. Numerous studies have been performed on the applications of low level lasers in patient pain reduction. Mechanisms of pain reduction with therapeutic lasers and their application are expressed, and the studies realized in this field are presented.


LLLT; endodontic; laser


Mokmeli S. Lasers classification, Eslami Faresani R. Rezvan F. The principals of low level laser therapy.Iran, Boshra 2004.

Eslami Faresani R. Ashtiani Araghi B. Kamrava K. Rezvan F. Laser Principles. Mokmeli S. Saghafi S. Laser therapy (handbook on basic and clinical practice of low level laser).Iran, Tehran, Boshra 2006.

Mester E, Mester AF, Mester A. The biomedical effects of laser application. Lasers Surg Med 1985; 5:31-9.

Tuner J, Hode L.The laser therapy handbook, Sweden, Prima Book AB 2007.

Eghbali F. Low level or theraputic lasers, Fekrazad R. Applying low level laser therapy in dentistry. Tehran:Shayan nemoodar; 2009.

Derr VE, Fine S. Free radical occurrence in some laser-irradiated biologic materials. Fed Proc. 1965; 24: Suppl14:99-103.

Ben-Dov N, Shefer G, Irintchev A, Wernig A, Oron U, Halevay O. Low energy laser irradiation affects cell proliferation and differentiation in vitro. Biochim Biophys Acta. 1999;1448(3):372-80.

Passarella S, Casamassima E, Molinari S, Pastore D, Quagliariello E, Catalano IM, et al. Increase of proton electrochemical potential and ATP synthesis in rat liver mitochondria irradiated in vitro by helium-neon laser. FEBS Letters. 1984; 175(1): 95-9.

Bolton P, Young S, Dyson M. Macrophage responsiveness to light therapy with varying power and energy densities. Laser Therapy. 1991; 3 (3): 105-12.

Karu T. Mechanisms of interaction of monochromatic visible light with cells. Proc SPIE 1996; 2630: 2-9.

Tadakuma T. Possible application of the laser in immunobiology. Keio J Med. 1993;42(4): 180-82.

Kovacs IB, Mester E, Gorog P. Laser-induced stimulation of the vascularization of the healing wound. An ear chamber experiment. experientia. 1974;30(4): 341-3.

Mester E.Biostimulating Effect of Laser beams. Z Exp Chir. 1982;15(2):67-74.

Carney SA, Lawrence JC, Ricketts CR. The effect of light from a ruby laser on the metabolism of skin in tissue culture. Biochim Biophys Acta.1967;148(2):525-30.

Saldo I, et al. Effects of GaAs- laser on murine sarcoma depends on tomour size. Lasers in surgery and medicine. 1989; Suppl. 1:40

Nanami T, Shiba H, Ikeuchi S, Nagai T, Asanami S, Shibata T. Clinical applications and basic studies of laser in dentistry and oral surgery. Keio J Med. 1993; 42(4):199-201.

Scherman A, Jacobsen PL. Managing dentin hypersensitivity: what treatment to recommend to patients.J Am Dent Assoc. 1992; 123(4):57-61.

Sandfo rd MA, Walsh LJ. Thermal effects during desensitization of teeth with gallium-aluminium-arsenide lasers. Periodontology. 1994;15:25-30.

Featherstone JD, Nelson DG. Laser effects on dental hard tissues. Adv Dent Res 1987;1(1):21-6.

Gerschman JA, Ruben J, Gebart-Eaglemont J. Low level laser therapy for dentinal tooth hypersensitivity. Australian Dental Journal.1994;39(6):353-7.

Tsuchiya K, Kawatani M, Takeshige C, Matsumoto I. Laser irradiation abates neuronal responses to nociceptive stimulation of rat-paw skin. Brain Res Bull. 1994;34(4):369- 74.

Matsui S, Tsujimoto Y, Matsushima K. Stimulatory effects of hydroxyl radical generation by Ga-Al-As laser irradiation on mineralization ability of human dental pulp cells. Biol Pharm Bull 2007;30(1):27-31.

Alipanah Y, Asnaashari M, Anbari F. The effect of low level laser (GaAlAs) therapy on the post-surgical healing of full thickness wounds in rabbits. Med Laser Application. 2011; 26(3): 133-8.

Ando T, Noguchi I, Satoh Y, Fuse S, Hayama S, Takahashi M,et al.Use of soft lasers in dentistry. Shikai Tenbo. 1985;66(6):1265-8. (Japanese)

Asnaashari M, Mohebi S, Paymanpour P. Pain reduction using low level laser irradiation in single-visit endodontic treatment. J Lasers Med Sci 2011; 2(4):139-43.

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.

Khullar SM, Brodin P, Barkvoll P, Haanaes HR.Preliminary study of low-level laser for treatment of long-standing sensory aberrations in the inferior alveolar nerve. J Oral Maxillofac Surg 1996; 54(1):2-7.

Schlager A, Offer T, Baldissera I. Laser stimulation of acupuncture point P6 reduces postoperative vomiting in children undergoing strabismus surgery. Br J Anaesth.1998; 81(4):529-32.

DOI: http://dx.doi.org/10.22037/2010.v4i2.4187