Quality of light - is laser necessary for effective photobiostimulation?

Is true laser, with its unique qualities of coherence, collimation and monochromaticity, necessary for effective photobiostimulation, or is a simpler form of light sufficient? Doubt has been cast on the importance of coherence and collimation in influencing biostimulation. It is hypothesised that monochromaticity (or singularity of wavelength) is the only characteristic of laser necessary for photostimulation. If wavelength is the important factor in phototherapy, the clinician must consider which wavelengths are capable of producing specific effects within living tissues. In addition, it is important to distinguish the quality of light provided by a unit and whether it will give the desired results without a large financial outlay. This article reviews the unique properties of laser, discusses their contribution to photobiostimulation and looks at apparatus which provide these properties.