Lasers vs. LED Posted on 4 Aug 00:00 , 0 comments

Lasers vs. LED

Light emitting diodes (LED) are just tiny light bulbs that fit easily into an electrical circuit. But unlike ordinary incandescent bulbs, they do not have a filament that will burn out. They are illuminated solely by the movement of electrons in a semiconductor material. LEDs produce incoherent light just like an ordinary light bulb does. Light from LEDs have very little tissue penetration compared to laser light.


By applying the first law of photochemistry (Grotthus-Draper Law), which states that light must be absorbed by a molecule before photochemistry can occur, one can immediately conclude that light from LEDs would work only on skin level conditions, if at all. For conditions deeper than skin layers one must choose light from a laser source.


Is Laser Therapy Scientifically Well Documented?

There are more than 120 double blind positive studies confirming the clinical effects of laser therapy. More than 300 research reports have been published. Looking at the laser therapy dental literature alone there are over 300 studies. More than 90% of these studies do verify the clinical value of laser therapy.


A review of the research literature of studies that produce negative results one finds that low dose was the single most significant factor. By dose is meant the energy of the light delivered to a given unit area during a treatment session. The energy is measured in joules and the area in cm2. Assuming that the power of the laser remains constant during the treatment, the energy of the light will be equal to the power in watts multiplied by the time in seconds during which the light is emitted. Therefore, a laser with more power (watts) can deliver the same amount of energy (joules) in less time.