In the experiment, the reaction of the rat oral mucosa to fractional mechanical and laser treatment performed by radiation of a diode laser with a wavelength of 980 nm in various combinations of the average power of laser radiation, the pulse duration and energy of the laser radiation, along with the fill factor was investigated. Optical and histological examination of the rat oral mucosa during its regeneration after fractional treatment was performed. It was found that on the 5th day after a single-shot fractional laser treatment, the number of mitotically dividing cells exceeds the number of those cells after a single-shot fractional mechanical treatment and in the control area. It has been found that on the 28th day after a three-fold fractional treatment, the surface of the mucosa is visually bleached, and after the laser treatment, the connective tissue of the mucosa lamina propria and the submucosal layer contains fibrous structures and cellular elements, mainly myo- and fibroblasts. It has been found that during the regeneration on the 28th day after a three-fold fractional laser treatment, the thickness of the epithelium and the thickness of the submucosal layer with lamina propria of mucosa increase in comparison with the control.