Comparative Evaluation of Treatment Outcome in Oral Lichen Planus Patients Using Diode Laser of 660 nm and 810 nm – In Vivo Study

Background Oral lichen planus (OLP) is a chronic immune-mediated mucosal disorder with recurrent pain and erythema. Corticosteroids, though effective, have adverse effects and recurrence risk. Photobiomodulation therapy (PBM) using diode lasers has emerged as a non-invasive alternative. This study aimed to compare the clinical efficacy of 660 nm (red) and 810 nm (near-infrared) diode lasers in the management of symptomatic OLP. Materials and Methods Ten patients (5 males, 5 females; mean age 49.7 ± 14.5 years) with clinically and histologically confirmed symptomatic OLP underwent PBM therapy. Each patient received 660 nm laser treatment on the right buccal mucosa and 810 nm laser treatment on the left side once weekly for five weeks. Clinical assessments were performed using the Visual Analog Scale (VAS) for pain, Thongprasom scoring for lesion severity, Escudier criteria for site and activity, and pigmentation changes. Data were analyzed using Friedman and Wilcoxon signed-rank tests ( p  < 0.05). Results Both wavelengths produced statistically significant reductions in pain (VAS: 7.1 ± 1.6 → 0.8 ± 1.3; p  < 0.001) and lesion severity (Thongprasom: 3.3 ± 1.1 → 1.9 ± 1.0; p  < 0.001). No intergroup difference was observed between wavelengths. Pigmentation increased mildly, consistent with post-inflammatory healing. No adverse effects occurred. Conclusion Both 660 nm and 810 nm diode lasers demonstrated equivalent and significant improvement in pain and lesion severity, confirming PBM as an effective, safe, and well-tolerated adjunct for managing symptomatic oral lichen planus.