Comparação entre protocolos de terapia fotodinâmica antimicrobiana como tratamento adjunto no manejo de pericoronarite inicial: estudo clínico randomizado, controlado, duplo cego

Abstract

Pericoronitis is common during the eruption of third molars, affecting quality of life. Despite local and systemic damage, the literature on treatments is limited, with no defined gold standard. Antimicrobial photodynamic therapy (aPDT) is an effective and easy-to-perform alternative that does not cause bacterial resistance. Methylene blue, used in aPDT, has been studied in a new oral formulation whose composition prevents aggregation with promising photochemical and photophysical effects. This study aimed to evaluate the effectiveness of two aPDT protocols with different methylene blue formulations in initial pericoronitis through microbiological, clinical, and immunoregulatory analysis, as well as the impact on oral health-related quality of life using the OHIP-14 (Oral Health Impact Profile - 14) questionnaire. This randomized, controlled, and double-blind clinical trial was conducted with 34 young, healthy patients with pericoronitis. The groups were: G1 (positive control, n=17), irrigation with saline solution and aPDT with conventional methylene blue (0.005%, laser λ=660 nm, 9J per point, 318 J/cm²), and G2 (experimental, n=17), using the same therapy but with a patented new formulation of methylene blue. QRT-PCR performed microbiological analysis for Tannerella forsythia and Universal 16S. Interleukins and chemokines (IL-1β, IL-6, IL-8, TNF-α, IFN-γ, IL-17, IL-10, IL-12) were evaluated using LUMINEX® at baseline and on the 4th day after aPDT. Both groups showed significant improvement in pain (G1: p=0.022; G2: p=0.001) and mouth opening (G1: p<0.001; G2: p=0.002). There was no significant difference between G1 and G2 for pain and mouth opening (p=0.845 and p=0.318, respectively). A significant reduction in IL-1β (p=0.001) and in the number of Universal 16S copies in the G2 biofilm (p<0.001) was observed. No statistical differences were found within or between groups for other parameters. Both aPDT with the traditional and the new methylene blue formulations effectively reduced pain and improved mouth opening. In the group that used the new methylene blue formulation, there was a significant reduction in IL-1β levels and Universal 16S copies in the biofilm.