[Laser in periodontology: theoretical-experimental approach. 3. Experimental study of the effects of He-Ne (638 nm) and infrared diodic (904 nm) lasers on the gingival mucosa of rats].

Medical and surgical laser-therapy is becoming more and more important in various branches of Medicine, however independently from clinical results still very little is known about physical-biological interaction between laser beam and living matter. The aim of this study is of finding tissutal and cellular effects of stimulation with soft and mid laser. The study started from an original work carried out at the Institute of Biology of the 1st Faculty of Medicine and Surgery of Naples University from which appears the possibility of visualizing the stage of nuclear active synthesis of the cell, simply by Maloory tricromic colouring. By this method the cellular nucleuses take, usually, a red colour, however in presence of an increase of the RNA nuclear synthesis the nucleuses take a typical blue colour. The importance of the study induced us to research the presence in the oral mucose of the rat after radiation as an effect of biostimulation. The results of this study showed and increase of the epithelial cheratine and a variation of the disposition and of the number of the precheratine grains in treated site. The blue nucleuses have been found at the basal level without any difference between treated and control site. On the other hand their presence is the normal consequence of the epithelial evolution which starts from the basal level which is the most active in the stage of nuclear synthesis.