Recurrent aphthous stomatitis (RAS), is characterized by recurrent, ulcerative oral lesions which are often painful, single or multiple, round or ovoid ulcers, present during childhood or adolescence and recurs for variable periods of time. Discomfort in patients with RAS is relatively high. The patients' life quality is affected by painfulness of these mucosal lesions.The presence of ulcerations increase the flow of saliva, and interfere with eating,...