<prompt> Which of the following is not a modification for the class III cavity preparation to receive direct filling gold restorations?Ferrier designLoma Linda designIngraham designMoustache extensions  <response>: Class V with unilateral or bilateral moustache extensions occlusally:Sometimes surface defects occlusal to the height of contour are continuous with a gingival third lesion, necessitating their involvement in the Class V cavity preparation and their restorations. So one or two occlusal extensions are added to the basic trapezoidal Class V cavity preparation. 