 The primary objective of the study is to determine the efficacy of dexamethasone rinse in reducing pain in patients with oral lichen planus. Secondary objectives are to evaluate a novel scoring system of severity of lichen planus, assess the changes in salivary biomarkers associated with the treatment, assess the impact of oral lichen planus on the quality of life using the SF-36 instrument and the Oral Health Impact Profile OHIP-14. 