[Histopathological study of wound healing process of rat tongue and femur by excimer laser irradiation--possibility of cutting of vital tissue by laser irradiation].
The possibilities of bone and soft tissue ablation without thermal damage by 248 nm KrF excimer laser irradiation were examined. A defect was made on the rat tongue by laser at pulse width: 15 nsec, power density: 12 W/cm2, pulse repetition rate: 20 Hz and irradiated time: 60 seconds. The same size defect was made by stainless steel surgical knife for control. The tongues were examined histopathologically at timed sequence from 1 hour to 7 days after operation. The rat femur was cut by laser at pulse width: 15 nsec, power density: 2.6 kW/cm2, pulse repetition rate: 30 Hz and irradiated time: 3 minutes. The femur was amputated by dental diamond disc for control. The femurs were examined histopathologically at timed sequence from 1 hour to 16 weeks after operation. The rat tongue was easily excised with little thermal injury by laser irradiation, and its healing process is almost the same as that of the control. The laser irradiation had no hemostatic effect. The femur could be amputated by laser irradiation but its wound healing was prolonged. The laser ablation stump showed massive necrosis probably due to the thermal injury and these necrotic bones likely disturbed the wound repair. The degree of the thermal injury by the excimer laser irradiation might depend on the irradiation condition because the condition of bone amputation was stronger than that of tongue excision.
Ochiai
S
S
Department of Oral Pathology, Faculty of Dentistry, Tokyo Medical and Dental University.
D000818:Animals; D005269:Femur / Q000473:pathology* / Q000502:physiology; D053685:Laser Therapy; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D014059:Tongue / Q000473:pathology* / Q000502:physiology; D014945:Wound Healing