Which of the following is not a modification for the class III cavity preparation to receive direct filling gold restorations?
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.
Ferrier design
Loma Linda design
Ingraham design
Moustache extensions