Background: Low-level laser therapy (LLLT) has been applied for the management of craniomaxillofacial disorders, including intraoral wounds, as well as recurrent aphthous stomatitis (RAS) lesions. However, the proper combination of laser features and tissue characteristics remains the major challenge in the realm of photobiomodulation (PBM).
Objectives: The aim of the present study was to assess the feasibility of neodymium-doped yttrium aluminum garnet (Nd:YAG) laser therapy in treating RAS lesions, and to compare 2 techniques, different with regard to the distance between the fiber tip and the ulcer.
Material and methods: A total of 138 patients (94 males and 44 females) with untreated RAS were divided into 3 groups: focused laser (energy density: 48 J/cm2; power density: 0.797 W/cm2; spot size: 0.1256 cm2); defocused laser (energy density: 21 J/cm2; power density: 0.354 W/cm2; spot size: 0.2826 cm2); and placebo. In the focused group, laser irradiation was performed with the laser tip kept 1 mm away from the lesion. Acrylic cylinders were prepared to precisely fit the handpiece tip and hold it in the proper position. In the defocused group, acrylic cylinders were prepared to set the laser tip 6 mm away from the lesion to obtain defocused irradiation. Finally, in the placebo group, a routine laser therapy procedure was carried out with a helium-neon (He-Ne) red light laser. The lesion size, and pain intensity and duration were recorded.
Results: Photobiomodulation showed a significantly more efficient pain relief as compared to the placebo group (p < 0.001) and also significantly better results in decreasing pain duration (p < 0.001). Besides, the diameter of the lesions in the exposed cases decreased during the 3 consecutive days of the study, while an increase in the diameter of the lesions was noticed in the placebo group.
Conclusions: The Nd:YAG laser therapy, with the conditions and adjustments of the present study, may be successfully applied to manage RAS lesions, using either focused and defocused scanning techniques.
Keywords: aphthous stomatitis; lasers; low-level laser therapies; oral medicine; solid-state.