Violation
To achieve optimum strength and esthetics, a porcelain fused to metal restoration with a porcelain butt joint margin requires a 1. 0.8 - 1.2mm shoulder. 2. sharp, well defined axiogingival line angle. 3. 90?- 100? cavosurface margin. 4. finish line that is 2mm subgingival.
(1) (2) (3)
(1) and (3)
(2) and (4)
(4) only
All of the above