A photograph of a crown shows a defined space on the internal surface of the casting. What is this?

Patient case: Analgesia, paediatric trauma and restorative decisions

Scenario: Four items, three of them treatment decisions.

Show answer and explanation

Correct answer: A. Die spacer relief for the cement film

A. Correct. Die spacer is painted onto the die, short of the margin, to create deliberate internal relief. Without it, the cement cannot escape and the crown will not seat completely.
B. An open margin is a gap at the finish line, visible at the periphery rather than internally.
C. Casting porosity appears as voids within the metal itself, not as uniform internal relief.
D. Overcontouring is an external form problem that causes plaque retention and gingival inflammation.

Note: Spacer is kept about 1 mm short of the margin so that marginal adaptation is unaffected.