Effect of laser irradiation on aphthae pain management: A four different wavelengths comparison

Recurrent Aphthous Stomatitis (RAS) is an oral condition characterized by painful ulcerations of the mucosa, healing spontaneously in 10-14 days but sometimes, due to their number, size and frequency of recurrence, lesions may be the cause of a severe disconfort with an impact on the quality of life of the patients due to the increased difficulty to eat, swallow and speak. For RAS, different protocols and treatments have been proposed as standard topical treatment to provide symptomatic relief, immunomodulating drugs as thalidomide, colchicine and steroids have been also proposed with the outcome to relief the pain, accelerating the healing process and increase the duration of ulcer-free period but without definitive results and without side effects. In this study we analysed the effect of laser treatment of aphthous lesions with four devices available on the market, two with wavelength in the infra-red region (2940 nm 808 nm) and two with a wavelength in the visible region (450 nm and 635 nm). Diode lasers 808 nm and 450 nm defined almost the same results with an improvement starting already after the application and gradually improving until 7 days after treatment without any statistically significant difference between them. Diode 635 nm was the device gaining the earliest effect reducing the pain already during the treatment and maintaining it at low level immediately after the laser application and after 3 and 7 days with levels of pain comparable with them obtained with 808 nm and 450 nm lasers. Er:YAG laser with the used parameters obtained a pain relief only during the treatment. The originality of this study was to compare different laser wavelengths, some of them never used for this purpose, and to compare also the two different ways to use lasers, the photobiomodulation (LLLT) and the high-power irradiation.