  After the discovery of laser therapy it was realized it has useful
application of wound healing and reduce pain, but due to the poor understanding
of the mechanism and dose response this technique remained to be controversial
for therapeutic applications. In order to understand the working and
effectiveness different experiments were performed to determine the laser beam
effect at the cellular and tissue level. This article discusses the mechanism
of beam interaction at tissues and cellular level with different light sources
and dosimetry principles for clinical application of low level laser therapy.
Different application techniques and methods currently in use for clinical
treatment has also been reviewed.
