Recurrent aphthous stomatitis (RAS) is a common disease with ulcers in oral cavity which may trigger chewing, speaking, and swallowing difficulties to patients. Treatment of RAS is primarily aimed at pain relief and the promotion of wound healing. However, few agents have been found to have definite effect in the management of RAS and most of the medicinal products may cause adverse reactions or other disadvantages, which makes their clinical usage questionable. The purpose of this randomized controlled clinical trial (RCT) was to assess the clinical effect of diode laser and traditional medication treatment on RAS. In this study, 56 patients were randomly assigned to two groups (n = 28). Laser group was treated using diode laser (810 nm, 1.0 W, CW, irradiation time 20 s for 3 applications) once daily for continuous 3 days. Medication group was treated with triamcinolone acetonide 0.1% three times a day until the lesion was healed. Spontaneous and functional pain level on the third day of treatment was significantly less in the laser group. Significant difference was observed with respect to healing time; however, the order of difference is small albeit of statistical significance. Diode laser with the chosen parameters had better effects on pain relief and no distinct advantage on wound healing comparing with medication. Trial registration number: ChiCTR2000030298; date of registration: 26 February 2020 (retrospectively registered)
