Comparative evaluation of the effects of ultrasonic and ultraviolet irradiation on tissue regeneration.

Twenty rabbits were divided into two matching groups. Holes of 1 cm2 area were bored through the full thickness of the pinna of both ears in each rabbit. In group I, the right ears were irradiated with pulsed ultrasound three times/week for 18 weeks. In group II, the right ears were irradiated with ultraviolet rays using a hot quartz lamp, three times/week for 18 weeks. The left ears in all rabbits were not irradiated and acted as controls. The rate of wound healing was calculated in terms of decrease in surface area of the wounds measured with a planimeter from enlarged photographs taken from the wound edges at the end of third, fifth and seventh weeks. The results revealed that ultrasound has a better effect on promotion of tissue regeneration than ultraviolet irradiation, as evidenced by both reduction in the surface area of wounds and by histopathological examination.