en Dentistry Dentistry پژوهشي Research <div><strong>Introduction:</strong> It is widely accepted that recurrent aphthous stomatitis (RAS) is the most common recurrent oral ulcer. Since none of the various symptomatic therapies recommended for painful periods can affect the etiology of the disease, the goal is only to reduce the severity of the pain, irritation, and duration of the ulcers. The purpose of this study was to compare the effects of tetracycline and <em>Myrtus communis</em> extract (<a name="_Hlk65226543"><em>Myrtex</em></a>) on the treatment of RAS.<br> <strong>Materials and Methods:</strong> The patients (n=54) enrolled in the study consisted of two groups of 26 and 28 people who received tetracycline and <em>Myrtex</em>, respectively. The case group received <em>Myrtex</em> solution and the control group received 250-mg tetracycline capsules. The patients in both groups kept the drug on the ulcer for 30 seconds four times a day. They answered the visual analogue scale (VAS) on days 0, 2, and 6 and were clinically examined to check any chenges in ulcer size and healing.<br> <strong>Results:</strong> According to VAS analysis, the pain and irritation levels in the <em>Myrtex</em> group were 34.8% less than in the tetracycline group (P<0.02). The ulcer size was 40% higher on the second day in the <em>Myrtex</em> group than in the tetracycline group, which was statistically significant (P<0.02), but the ulcer size changes on the sixth day of follow-up were not statistically significant (P<0.15).<br> <strong>Conclusion: </strong>According to the study, the administration of <em>Myrtex</em> is more effective in reducing the severity of pain and irritation and improving the quality of life. Therefore, it is recommended to prescribe <em>Myrtex</em> (<em>Myrtex </em>5%) on the basis of the mentioned method for the treatment of minor aphthous.</div> Recurrent aphthous stomatitis, Tetracycline, Myrtus communis extract, Visual analogue scale, Ulcer duration 20 26 http://jbrms.medilam.ac.ir/browse.php?a_code=A-10-482-1&slc_lang=en&sid=1 Leila Rajaei-Behbahani 10031947532846007745 10031947532846007745 No Department of Oral and Maxillofacial Medicine, Faculty of Dentistry, Jundishapur University of Medical Sciences, Ahwas, Iran Farid Abbasi 10031947532846007746 10031947532846007746 No Department of Oral and Maxillofacial Medicine, Faculty of Dentistry, Shahed University of Medical Sciences, Tehran, Iran Maryam-Sadat Sadrzadeh-Afshar 10031947532846007747 10031947532846007747 No Department of Oral and Maxillofacial Medicine, Faculty of Dentistry, Aja University of Medical Sciences, Tehran, Iran Sara Rajaei-Behbahani 10031947532846007748 10031947532846007748 No Department of Oral and Maxillofacial Medicine, Faculty of Dentistry, Jundishapur University of Medical Sciences, Ahwas, Iran Shahla Afshar sadrzadehafsharmaryamsadat@gmail.com 10031947532846007749 10031947532846007749 Yes Oral and Maxillofacial Medicine Specialist, Tehran, Iran