Photodynamic therapy decrease immune-inflammatory mediators levels during periodontal maintenance

Antimicrobial photodynamic therapy (aPDT) was introduced as a promising adjuvant therapy on the periodontal treatment. The aim of this study was to evaluate the effect of aPDT on inflammatory mediator levels in residual periodontal pockets of patients with severe chronic periodontitis under periodontal maintenance, during 12 months follow-up. A randomized controlled trial study was conducted in 28 patients with severe chronic periodontitis. After non-surgical periodontal treatment, patients with at least four teeth with residual pocket probing depth (PPD) ≥4 mm were randomly assigned to either aPDT or control group. The aPDT (low power laser: 660 nm, 40 mW, 90 J/cm², methylene blue 0.01 %) was performed at baseline and 3, 6, and 9 months. Clinical parameters were collected before and 3 and 12 months after the intervention, and gingival crevicular fluid was collected in the same times, including 1 week after the intervention. Immunological evaluation was carried out using the Luminex assay which quantified the expression of ten cytokines: interleukin (IL)-1α, IL-1β, IL-8, IL-1ra, fibroblast growth factor (FGF), vascular endothelial growth factor (VEGF), interferon (IFN)-γ, tumor necrosis factor (TNF)-α, IL-4, and IL-10. All clinical variables showed significant improvement for both groups, but there was no statistical difference between groups with no clinical benefits. IL-1α, IL-1β, IL-8, and VEGF showed significant differences (p < 0.05) between groups, whereas IL-1ra mediators, IFN-γ, and IL-10 demonstrated a statistical difference (p < 0.01) over time in the same group. At any time, FGF, IL-4, and TNF-α showed no statistical difference between groups (p > 0.05). aPDT therapy can improve the benefits on inflammation control during the periodontal maintenance.