What is the primary function of a die spacer in crown preparation?

• A. To seal the margin
• B. To increase cement retention
• C. To create space for cement between crown margin and tooth
• D. To sharpen the margins

Answer: (C)

The main idea is that a die spacer is used to create space for luting cement between the prepared tooth and the crown. By applying a thin, even layer to the tooth surfaces and margins, you establish a consistent cement film thickness, typically a very thin layer, which allows the crown to seat fully without binding while still providing enough space for the cement to fill. This helps ensure proper seating and retention without overly thick cement. It does not seal or sharpen margins, and it isn’t intended primarily to increase retention.