Abstract: A fiber optic illumination system for dental instruments of the present invention enables a light source to provide light to the oral cavity using a single continuous polymethyl methacrylate optical fiber axially fitted into a cylindrical tube, open at both ends, and affixed to a dental instrument, such as a mirror, aspirator, or retractor, for example. The end of the cylindrical tube and the inserted portion of the single continuous polymethyl methacrylate optical fiber it supports contacts the fluids in the oral cavity. After treatment, the end of the single continuous polymethyl methacrylate optical fiber is removed from the cylindrical tube and immersed into a 1:4 glutaraldehyde, or equivalent, solution and subsequently wiped clean. The dental instrument and attached cylindrical tube, now devoid of optical fibrous material, is completely and fully sterilized in a normal fashion, such as by autoclaving.