炭酸ガスレーザー照射による家ウサギ舌組織の変化に関する基礎的研究

Abstract

A 2 mm spot size focused beam from a continuous wave surgical carbon dioxide laser with diameter, integrated with an operating microscope was used to evaporate the normal dorsal surfaces of rabbit tongues under different conditions. The immediate effects of irradiation with carbon dioxide laser on the dorsal surface of the tongue were studied macroscopically and microscopically, and wound healing was examined microscopically, 1, 3, 5, 7, 14 and 21 days after he laser irradiation. The results were as follows.1) The immediate change induced by a focused beam carbon dioxide laser was characterized by white coloration on the targetarea up to a laser emission of 1 Joul and by tissue defect formation when emission exceeded 2 Joul.2) Tissue defect was characterized by a cone shape, and the floor of the defective was portion was slightly elevated at its center in some cases. The margin of the defective portion was slightly elevated over surrounding normal tissue.3) The depth of tissue defect varied with output power and irradiation time. In the same output power, the depth of tissue defect was directly proportional to irradiation time.4) Microscopic findings immediately after the laser irradiation varied with irradiation conditions. At 5 watts 0.1·0.2·0.5 second and 10 watts 0.1 second laser irradiations, tissue damage was only seen at the prickle-cell layer of the mucosal epithelium and the basal layer was not damaged. At 5 watts·1.0 second, 10 watts·O.2 second, 15 watts·O.1·0.2 second and 20 watts 0.1 second laser irradiations, tissue damage was seen beyond the basement membrane and in the submucosal layer, but the muscle layer was not damaged. At 10 watts 0.5·1.0 second, 15 watts·0.5·1.0 second and 20 watts·0.2·0.5·1.0 second laser irradiations, the muscle layer was damaged.5) Wound healing differed according to the depth of tissue damage immediately after the laser irradiation mentioned above. Wound healing was fast and finished within 7 days after the laser irradiation in the group that tissue damage was limited only to the prickle-cell layer of the mucosal epithelium. In the group that tissue damage was seen beyond the basement membrane and in the submucosal layer, and did not extend to the muscle layer, wound healing finished within 14 days after laser irradiation, but in the group that tissue damage extended to the muscle layer, 21 days were necessary to complete wound healing.From these results, it is speculated that the carbon dioxide laser will be effective to remove superficial lesions of the oral mucosa and of benefit to oral and maxillofacial surgery.