[Significance of the angle of the CO2 laser beam, experimental studies in the oral cavity]

Abstract

In the mouth cavity of white rats the surface extension and depth of the defect brought about by laser beam arriving at various angles of incidence have been examined by means of hand- and operational microscopy and micro manipulator, respectively. In case of an angle of incidence of 90 degrees at the same energy, exposition time and focusing the forming crater is the deepest and the surface diameter the smallest. The more the angle of incidence of obliquely incident race deviates from 90 degrees, the more diminishes the depth of the lesion and increases its surface. Sparing of the surrounding healthy tissues and exact removal of pathological tissues at the surface and in the depth can best be obtained by a ray incident at 90 degrees. Thus, the operation not only spares the tissue but permits to keep the surrounding structures and, thus, the functions intact. Where an incidence at 90 degrees cannot be ensured by direct ray guiding, it is preferable to let the laser ray reach the tissue surfaces in a range of angles near 90 degrees.