ABSTRACT
The oral cavity has been susceptible to microbial infections since ancient times. These include gingivitis, dental caries, and periodontitis, often leading to tooth and alveolar bone loss. Several oral bacteria are involved in the causation of these infections and are treated with antimicrobials. However, bacteria have developed resistance over the period to several conventional antimicrobial drugs. This is mostly attributed to the formation of biofilm and the production of virulence factors through quorum sensing (QS) system, thus posing challenges to clinicians in treating these infections through conventional methods. Photodynamic therapy (PDT) involves the activation of dye or chemicals with the use of a light source at a specific wavelength which destroys the bacterial cells without affecting the host tissue. It acts on the bacterial cell wall by generating reactive oxygen species or free radicals. These dyes or chemicals usually have an affinity or binding capacity to bacteria and less chance of developing bacterial resistance. Several agents have photodynamic properties; however, each should be validated prior to utilisation in PDT. PDT for oral microbes is a promising tool for reducing the oral microbial disease burden.
