Lavaee F, et al. - Researchers conducted this randomized double-blind clinical trial to compare the impact of photodynamic therapy with topical corticosteroid in patients with oral lichen planus. The study sample consisted of 8 patients with bilateral oral lichen planus lesions. To assess the treatment outcomes, Mann-Whitney test was used. In addition to standard methods, photodynamic therapy could be used as an alternative therapy or as a new method for refractory oral lichen planus.