method and apparatus for disinfecting and / or sterilizing a root canal system by targeting the water content of disease and debris in the canals . the laser technique of employs a frequency of the wavelength emissions between about 930 to about 1065 nanometers with an optimum of 980 nm . this range of wavelengths targets the water content of tissue cells and pathogens as well as any residual organic debris in water within the root canal system after its preparation while being poorly absorbed by the surrounding dentin . the selection of the optimum wavelength produces significant effects generating and advancing treatment to the targeted aqueous environments . this is due to the rapid energy absorption by the water and the subsequent creation of gas bubbles , liberation of heat and subsequent propulsion of waves of heat and gas that impact along the canal walls and ramifications resulting in an enhanced bacterial kill and cleaning of the canal walls and ramifications . no dyes or other additives are necessary to enhance the effectiveness of the laser kill of bacteria , etc .