Low Level laser Light Therapy (LLLT) is an internationally accepted name for biostimulation with low energy lasers in order to achieve therapeutic desired effects. Traditionally, LLLT falls under the realm of Physical Medicine, which uses stimulation therapy to activate the body's natural defense mechanisms. When LLLT is the stimulus, the treatment modality is known as PHOTOBIOSTIMULATION.

LLLT has been indicated in sports medicine, physical/manual medicine, dermatology and neuroendocrine disorders in human and animal patients. The anti-inflammatory and analgesic properties of LLLT, as well as its effect on collagen formation, are good indications for LLLT in traumatology, surgery and dentistry, especially after major operations.

LASER

The word Laser is actually an acronym which stands for Light Amplification by Stimulated Emission of Radiation. Laser generates extremely pure light, i.e. light of one wavelength, not of an entire spectrum like a light bulb. The light emitted is highly organized in flow (It may help to think of laser as a single malt scotch and not a “blend” of different wavelengths of light). Laser can be any wavelength of light, visible or invisible, high energy or low energy.

In 1917, Albert Einstein introduced his basic theory for stimulated emission of electromagnetic radiation. This theory was verified by Landberg in 1928, but at the time there were no practical possibilities for producing a functional laser. In 1951, Fabrikant, a Russian physicist submitted a patent application and subsequently published a paper on laser in 1959.

Mester, a Hungarian scientist, was the first to publish a series of articles in 1960 on the biostimulatory effect of LLLT on cell cultures. In 1963, he published the results of animal experimentation which showed that re-growth of epithelium over skin lesions was faster if the lesion was irradiated with1 Joule per square centimeter. Higher doses did not give any better effect. In fact, if the dose was increased many-fold the result was the opposite. Wound healing was inhibited.

In 1965, Laor and his team found that laser irradiation (LLLT) stimulated the rate of healing burns and mechanically induced wounds.

PHYSICS 101

A Laser is a device which produces electromagnetic radiation in the light band. Electromagnetic radiation is a form of energy flux which has properties of both a wave and a particle. These Wave-Particles are called PHOTONS.

Photons have a certain amount of energy (E) which unifies these two properties of waves and particles. Energy (E) is proportional to the mass of the photon (m) according to Einstein's famous equation:

E=mc2

Energy (E) is also proportional to the frequency (f) of the photon according to the equation:

E=hf

Since f x wavelength equals c (speed of light), it follows that f=c/wavelength. Substituting above, E is proportional to 1/wavelength, or the Energy of a photon is INVERSLEY PROPRTIONAL to its wavelength.

Thus, the BIGGER THE WAVELENGTH OF A PHOTON, THE SMALLER IS ITS ENERGY.

When a PHOTON hits an object, what happens to its energy? If the photon (light) reflects from the surface of the object, the photon retains its energy. If the photon is transmitted further (beyond the object), it likewise retains its energy. If the photon gets absorbed by the object however, its energy is delivered to the atoms and molecules of the object.

Depending upon the wavelength (and hence the energy) of the absorbed photon, several scenarios may occur. This absorbed energy may result in heat oscillations, i.e. the atoms/molecules become hot, if the energy is low. If the absorbed energy is higher, the atoms and molecules of the object can become excited and/or ionized. If the energy absorbed is high, it can cause the break up of chemical bonds in the atoms/molecules of the object and result in the formation of new compounds.

Laser light then, consists of photons of a specific wavelength, i.e. PURE LIGHT, and hence, a specific energy level, which can interact with a given object. The results of that interaction are dependent upon this specific wavelength (energy level).