Photosensitizing agents for medical and/or dental applications, namely, pharmaceuticals for the treatment of infectious diseases in the oral cavity; light-activated disinfectant compositions for killing disease-causing micro-organisms in the oral cavity; light-activated therapeutic preparations for killing bacterial, fungal and viral infections in the oral cavity; photosensitizers for use in photodynamic therapy and/or photodisinfection; namely, pharmaceuticals for the treatment of infectious...