A method of making a mold for use in the manufacturing of appliances for use in filling endodontically prepared root canals including the steps of drilling spaced apart holes into a flat base member, inserting into each of the holes elongated metal patterns having the desired configuration of a filler covered carrier shaft portion of an endodontic appliance, forming a vessel with the base member as the bottom and the patterns extending upwardly therein, pouring liquid plastic and a catalyst into the vessel and allowing it to solidify to form a mold, and removing the mold from the vessel and from the base, the mold having a cavity therein for each of the patterns, each cavity being useful for forming an appliance for use in filling an endodontically prepared root canal.