Evaluation of antioxidant efficacy of Purslane extract in Patients with Recurrent Aphthous Stomatitis: a randomized, placebo-controlled, triple-blinded, clinical oleh Mahsa Mohammadzadeh, Nima Rezaei, Elnaz Kamran, Faraneh Abdolhoseinpour, Isaac Firooze Moqadam, Shamsolmoulouk Najafi