ASSESSMENT OF THE PROLIFERATIVE ACTIVITY OF ORAL MUCOSAL TISSUES OF EXPERIMENTAL RATS RECEIVING RADIOTHERAPY FOLLOWING CO2 LASER THERAPY BY IMMUNOHISTOCHEMICAL AND HISTOPATHOLOGICAL STUDIES

Abstract

This study was perfomed to assess the healing process and the proliferative activity of the laser and the scalpel incisions wounds of the oral mucosa of eighty experimental rats receiving a single dose of 1750 rads of gamma rays by histopathalogic and immunohistochemical studies using Ki-67 as a biologic marker to identify the degree os proliferation . The animals were randomly divided into two main groups. Laser group (group I) wich consist of forty rats and scalpel group (group II) and consist of the remaining forty rats. A laser surgery was performed for the total forty rats of (group I) using a focused CO laser beam of 6 watts power to excise a biopsy of about 2x2 mm from the lower anterior labial vestibule. Another forty similar scalpel surgeries were made by sterile No 11 blade for the scalpel group (group II). Only ten biopsies from each • group were prepared to show the immediate effect of both scalpel and laser surgeries by histological and immunohistochemical studies. Ten animals were sacrified from each group after one week, two weeks and three weeks intervals and specimens were collected and prepared for both histologic and immunohistochemical studies. The results were confirmed by the image and statistical analysis. Histological sections (Ki-67 stained specimens) were examined by the image analyzer computer using the software Leica Qwin 500 to measure • the immunoreactivity of Ki-67 in the from of area % of a standard measuring frame. Also the intensity of the reaction was measured by the optical density in the nuclei. These data were collected, tabulated and statistically analysed by student T-test.