Relevance. Fractional laser technologies are very popular. The ability to create microchannels (coagulation or ablative nature) in the tissue by laser radiation stimulating its regeneration is the basis of fractional technology. The histological structure of the rabbit parietal bone during its regeneration after Laser Patterned Microcoagulation treatment was investigated by hematoxylin and eosin (H&E) stain.

Purpose. This in vivo study investigated the regeneration of the rabbit’s parietal bone after fractional laser treatment using diode lasers with wavelengths 980 nm and 1550 nm.

Materials and methods. A study was performed on the bone tissue of 10 laboratory animals (rabbits) using laser fractional treatment with wavelengths 1.55 and 0.98 μm. As laboratory animals (rabbits) were used Soviet chinchillas weighing 2.5-3 kg. 2 different lasers were used: FONALaser (Sirona Dental Systems, Germany) with a wavelength of 980 nm, a power of 5 W and a laser surgical device (LSP “IRE-Polyus”, Russia) with a wavelength of 1550 nm, a power of 25 W and a pulse width range from 60 to 250 ms.

Results. On day 21, the thickness of the periosteum in the group with a wavelength of 980 nm did not significantly differ from the thickness of the periosteum in the group with a wavelength of 1550 nm – p = 0.4000. On the 45th day of observation, there were also no significant differences in the thickness of the periosteum between both groups – p = 0.2000.

Conclusion. It was shown that the most destruction processes were noted by laser with a wavelength 1550 nm in the experiment without periosteum. The smallest changes were noted by laser with a wavelength 980 nm in the presence of periosteum. In this study, in 6 cases out of 10, the formation of young bone tissue as thin strip form at the bottom of the lesion site was noted.