Antimicrobial Photodynamic Therapy in Dentistry:
What do we Have for News?
Prof. Alessandra Nara de Souza Rastelli
Araraquara School of Dentistry, Sao Paulo State University-UNESP, SP, Brazil
Abstract
Photodynamic therapy (PDT) is a technique that combines a chemical compound or dye called photosensitizer with a visible or invisible light source, typically lasers or LEDs.
When molecular oxygen is present, the photosensitizer transitions from its ground state
to an excited state, generating reactive oxygen species (ROS) and singlet oxygen (¹O₂).
PDT is effective in eliminating unwanted eukaryotic cells, such as malignant cells in the
oral cavity, as well as pathogenic microorganisms involved in bacterial, fungal, or
parasitic infections. In dentistry, antimicrobial photodynamic therapy (aPDT) can be
utilized to manage biofilms associated with dental caries, periodontal and peri-implant
diseases, endodontic conditions, herpes simplex infections, candida infection, wound
healing, and oral lichen planus. During conventional aPDT, a solution containing a
photosensitizer is applied locally to the affected tissue. After a period of incubation, light
under an appropriate wavelength is then applied. Recently, a new approach called
Super Hydrophobic aPDT (SH-aPDT) has been proposed and successfully used
against periodontal biofilms. The key difference between conventional aPDT and SH-
aPDT lies in the method of delivering the photosensitizer to the tissues. The purpose of
this talk is to summarize the basic concepts and mechanisms of both conventional and
SH-aPDT, as well as their advantages, disadvantages, and current applications in
dentistry.
Learning Objectives
- Understand the definition, mechanisms and differences between conventional
aPDT and SH-aPDT. - Recognize the in vitro and in vivo application of SH-aPDT over periodontal
biofilms. - Apply how SH-aPDT can optimize antimicrobial killing with no staining of the
dental tissues and no cytotoxicity, and future perspectives.