Abstract: Capillary hollow fibers containing therein therapeutic and indicator agents and a method of employing such fibers, which method comprises placing the agent-filled, hollow capillary fibers into the oral cavity, and particularly about, adjacent or in contact with the teeth, at or about those areas where treatment of a dental disease is desired, or where indication of the presence of an oral or a dental disease is suspected, whereby such agent permeates from such capillary-hollow-fiber treatment into the localized area to treat the disease or to serve as an indication of dental disease in the area.