Pilot in vivo animal study of bone regeneration by fractional Er: YAG-laser

The histological structure of the rabbit parietal bone during its regeneration after fractional Er: YAG-laser (λ=2.94μm) treatment was investigated by hematoxylin and eosin (H&E) stain. In 48 days after fractional laser treatment, bone samples contained micro-cavities and fragments of necrotic tissue with empty cellular lacuna and coagulated protein of bone matrix. In this case, necrotic lesions appeared around the periphery of micro-cavities created by laser radiation. Fragmentation of detrital mass and partial substitution of micro-cavities with fatty bone marrow were observed in bone samples in 100 days after fractional laser treatment, in contrast to the earlier period. Partial filling of micro-cavities edges by fibrous tissue with presence of osteoblasts on their inner surface was observed in 100 days also, that indicates regenerative processes in the bone.