Nasrin Zand - Department of Medical Laser, Medical Laser Research Center (MLRC), Yara Institue, ACECR, Tehran, Iran
Mohsen Fateh - Department of Medical Laser, Medical Laser Research Center (MLRC), Yara Institue, ACECR, Tehran, Iran
Leila Ataie-Fashtami - Department of Medical Laser, Medical Laser Research Center (MLRC), Yara Institue, ACECR, Tehran, Iran
Parvin Mansouri - Department of Medical Laser, Medical Laser Research Center (MLRC), Yara Institue, ACECR, Tehran, Iran

Background and Objective: This randomized controlled clinical trial was designed to evaluate the effects of Non-Thermal CO2 Laser Therapy (NTCLT) to promote wound healing in recurrent aphthous stomatitis (RAS). Materials and methods: Fifteen patients with 30 aphthous ulcers completed the RCT. One of the ulcers was randomly allocated to be treated with NTCLT and the other one served as placebo. Before laser irradiation, both the laser and placebo lesions and their surroundings were covered with a thick layer of transparent, non-anesthetic gel with high water content. The CO2 laser beam (power: 1 W, defocused continuous mode, scanning the lesions with rapid circular motion of the handpiece) was illuminated throgh the gel. The placebo lesion was irradiated with the same laser, but with an inactive probe. The healing times of the lesions were recorded by a blinded physician. Results: The healing period was significantly shorter in ulcers treated by NTCLT than in those treated with placebo (p < 0.05). The process was pain free and no kind of anesthesia was required. There were no visible thermal complications after NTCLT and during follow-up periods. Conclusions: The results of this RCT suggest that single session of NTCLT could be used to promote wound healing in recurrent aphthous stomatitis without any visible side effects.