Bactericidal light

Summary form only given. Three methods of using intense light to destroy pathogens will be reviewed. 1. Ultraviolet destruction of viruses, bacteria, and the like. 2. Photodynamic therapy of photosensitized bacteria using exogenous photosensitizers. 3. Bacterial destruction in the near infrared of pigmented pathogens through selective photothermolysis: example of treatment for periodontitis. All three methods rely on the sensitivity to destruction by light of the pathogen being significantly lower than the sensitivity of the surrounding host tissues (favorable therapeutic ratio). Optical properties of host and pathogens will be discussed.