Abstract: A disc of semi-rigid material has side surfaces and a rounded working edge. The disc has minimum thickness allowing it to be forced into the contact areas between teeth for smoothening such areas and also allowing the working edge to remove excess bonding material in proximal areas. The disc is provided with a grip on the end opposite from the working edge. One or both of the side surfaces of the disc has abrasive means to assist in smoothening the contact areas. The instrument has an aperture therethrough for tying a retrieving line thereto. The grip is installed on the disc by injection molding, the disc having a pair of apertures therein through which molded plugs of the grip connect the side portions of the grip together and also securely attach the grip to the disc.The disc has also been used as a matrix in special cases so as to keep contact area free of excess restorative material.