For gold or ceramic restorations with at least 2 mm remaining dentin thickness, what is used?

• A. Cement
• B. Resin Composite
• C. Amalgam
• D. Glass Ionomer

Answer: (A)

The key idea is that seating a gold or ceramic crown on a tooth uses a luting cement to bond the restoration in place. When there is at least 2 mm of remaining dentin, conventional luting cement provides adequate seating, marginal seal, and pulpal safety without needing additional bonding agents. The cement fills the space between tooth and crown and helps secure the restoration through sealing and a little retention, which is sufficient given the dentin thickness. While other materials like resin composites are great for direct restorations or bonded restorations, and amalgam is a direct restorative, they are not used as the standard luting agent for crowns in this scenario. Glass ionomer can be used as a cement, but the general category applied here is cement to indicate the luting material used for crown fixation.