Effects of Photodynamic Therapy and Glucocorticosteroids on Salivary Oxidative Stress in Oral Lichen Planus: A Randomized Clinical Trial

<b>Objective:</b> This study aimed to assess the impact of photodynamic therapy (PDT) and topical glucocorticosteroids (GKS) on total oxidant status (TOS), total antioxidant capacity (TAC), and oxidative stress index (OSI) in the saliva of patients with oral lichen planus (OLP). <b>Methods:</b> Ninety patients with histopathologically confirmed OLP were randomly assigned to either the PDT group (<i>n</i> = 50) or the GKS group (<i>n</i> = 40). Unstimulated saliva samples were collected before treatment and at 1, 3, and 6 months post-therapy. TOS, TAC, and OSI were determined using colorimetric assays. <b>Results:</b> Both PDT and GKS significantly reduced TOS over the entire observation period. TAC decreased persistently after GKS but remained stable after PDT except for an initial decline. OSI was significantly lower immediately after PDT but did not show sustained differences. Overall, PDT more effectively and durably restored redox balance compared to GKS. <b>Conclusions:</b> Photodynamic therapy demonstrates superior long-term efficacy in modulating oxidative stress markers in saliva, supporting its role as a promising alternative to topical corticosteroids in managing OLP. Clinically, these findings suggest that PDT may offer a non-invasive, recurrence-reducing, and steroid-sparing treatment alternative for OLP, potentially improving long-term patient outcomes and reducing side effects associated with prolonged corticosteroid use.