The lateral surface of the body of rat mandibles was irradiated with CO2 laser with continuous discharges of 10 watts. After three months, the groove formed by the irradiation presented fused material with diverse fractures over a great extent. After seven months, the newly-formed periosteum covered wide areas of the incision that also presented carbonized material. One year following the incision, the newly-formed periosteum consisted of collagenous fibers that formed thick bundles transversal to the incision or regular meshworks covering the incision. Traces of carbonized material were verified also at this stage that were characteristic of retardment in bone regeneration
CO2 laser; Bone and bones; Microscopy, electron, scanning