SybronEndo's radioopaque gutta percha is the time-proven fill for your root canal therapies. Autofit Greater Taper Gutta Percha, developed by Dr. L. Stephen Buchanan, Autofit gutta percha is the latest innovation in filling materials. Greater Taper cones are designed to match canals shaped with Greater Taper files. Autofit cones have a parallel shank that is tapered to a point (similar to the end of a pencil). .