Photo-activated disinfection（PAD）, also known as photodynamic therapy or light-activated antimicrobial chemo-therapy, involves the use of a photoactive dye（photosensitizer） that is activated by exposure to light of a specific wavelength in the presence of oxygen. It is endowed with several favorable features for the treatment of infection in root canals, including a broad spectrum of antibacterial effect, the localization of its action, and the efficient inactivation of antibiotic-resistant strains. PAD provides an alternative approach to controlling root canal infection. This review summarized the mechanism of PAD and researches on its application in the inactivation of root canal bacteria.
