Journal of Japanese Society for Laser Dentistry
Online ISSN : 2185-6702
Print ISSN : 0917-7450
ISSN-L : 0917-7450
The Change of the Rat's Tongue by ArF Excimer Laser Irradiation
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1991 Volume 2 Issue 1 Pages 19-28


The purpose of this study was to investigate the changes of the tongue by ArF excimer laser irradiation.
ArF excimer laser was irradiated on the surface of the rat's tongue under the following irradiation conditions: wave length; 193 nm, output; 0.12 W, pulse repetition rate; 10 Hz, spot size; 1.0×3.3 mm, irradiation time; 60 seconds. We examined the thermal change on the tongue during laser irradiation by thermographs. The elevation of temperature on the surface of the tongue during laser irradiation was minimal. The maxium temperature rise was 33.8°C after 6 seconds. Histopathological and scanning electron microscopical studies were performed immediately, forty eight hours, one week and one month after the irradiation. Immediately after irradiation, the wound showed cleancut margins with little coagulation and necrosis tissue. Total removal of the epithelium was effected and, the superficial connective tissue and muscle fiber bundles had also been removed. Forty eight hours after irradiation, there was a clearly defined ulcer associated with bacterial infection. One week after irradiation, normal architecture and thickness of the epithelium was seen. Moreover, SEM findings revealed signs of recovery of the lingual papillae. One month after irradiation, rege nerated lingual papillae were observed over the surface of the wound. Neither inflammatory cell infiltration nor abnormality could be observed.
Because ArF excmer laser dose not demonstrate thermal injury, this finding seems to suggest a focarable condition for the healing process of wounds. The effectiveness of this laser can be attributed to the photoablation of tissues. However, there is much uncertainty about ultraviolet lasers, therefore more studies should be directed toward thes newtypes so it may be used in the clinical field in the future.

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