Non-Invasive Photodynamic Therapy against -Periodontitis-causing Bacteria

Area of Science:

• Oral Medicine
• Biomedical Engineering
• Photochemistry

Background:

• Periodontitis is a bacterial infection of the gums, often treated with invasive methods due to limited drug penetration.
• Biofilm formation and deep lesions in the gingival sulcus pose challenges for conventional antibacterial treatments.

Purpose of the Study:

• To develop and evaluate a non-invasive photodynamic therapy (PDT) for periodontitis using a photosensitizer-delivering ointment.
• To assess the efficacy of 650 nm LED light in activating the photosensitizer to eliminate key periodontopathic bacteria, Porphyromonas gingivalis and Fusobacterium nucleatum.

Main Methods:

• An optimized oral ointment formulation was created to deliver the photosensitizer, toluidine-blue-O (TBO), into the gingival sulcus.
• The penetration of 650 nm LED light through 3 mm of soft tissue and its activation of TBO were evaluated.
• In vitro and in vivo (rat models) studies assessed the efficacy of TBO-mediated PDT in reducing bacterial load, alveolar bone loss, and inflammatory cytokines.

Main Results:

• The 650 nm LED light effectively penetrated gingival tissue and activated the TBO formulation.
• The TBO ointment demonstrated efficient delivery and retention within the gingival sulcus.
• TBO-mediated PDT significantly reduced periodontitis-induced alveolar bone loss and inflammatory cytokine production in rats.

Conclusions:

• TBO-mediated photodynamic therapy using 650 nm LED irradiation is a viable non-invasive treatment for periodontitis.
• This approach effectively targets and eliminates bacteria within the gingival sulcus.
• PDT shows potential as a safe adjunctive therapy for periodontitis management.