OBJECTIVES: The aim of this study was to compare the effectiveness of two antimicrobial photodynamic therapy (aPDT) protocols using different methylene blue formulations in the treatment of initial pericoronitis. The research question was whether the new methylene blue formulation provides superior clinical outcomes compared to the conventional formulation. MATERIALS AND METHODS: This randomized, controlled, double-blind clinical trial involved 34 healthy young patients with pericoronitis. The following groups were established: G1 (positive control, n = 17), irrigation with saline solution and aPDT with conventional methylene blue (0.005%, laser λ = 660 nm, 9 J per point, 318 J/cm²); and G2 (experimental, n = 17), using the same therapy but with a patented new formulation of methylene blue. Pain assessed using the Visual Analog Scale (VAS) was defined as the primary outcome. Secondary outcomes include mouth opening, edema, and quality of life (OHIP-14). Microbiological and immunological analyses were performed to complement clinical outcomes. All outcomes were assessed at baseline and on the fourth day after aPDT. RESULTS: Both groups showed statistically significant improvement in pain (G1: p = 0.022; G2: p = 0.001) and mouth opening (G1: p < 0.001; G2: p = 0.002) after treatment. However, no statistically significant differences were observed between the groups in final pain and mouth-opening outcomes (p = 0.845 and p = 0.318, respectively). CONCLUSIONS: Within the limitations of this study, both aPDT protocols were associated with improvements in clinical outcomes. No between-group differences were observed in clinical outcomes; differences were limited to microbiological and immunological parameters, with no clinical superiority of the new formulation. CLINICAL RELEVANCE: Both methylene blue formulations may be used as adjunctive treatment options for the management of initial pericoronitis. However, no additional clinical benefit was observed with the new formulation, and these findings do not support a change in current clinical practice.
Schalch et al. (2026) studied this question.