FIG 2.

Schematic representation of antimicrobial photodynamic therapy using visible light (VIS) plus water-filtered infrared A (wIRA). Under the influence of a broadband VIS + wIRA radiator with a water-filtered spectrum in the range of 570 to 1,400 nm, the tested photosensitizers toluidine blue (TB) and chlorin e6 (Ce6) reached an excited-singlet state. Their activation led to an interaction with oxygen (O₂), which resulted in the production of various reactive oxygen species (ROS), like singlet oxygen. The latter are considered to intoxicate initially adherent microorganisms and resistant structures such as oral biofilms.