What is the difference between a preliminary and a final impression?

• A. Preliminary impressions are more detailed
• B. Final impressions are used for creating restorations
• C. Preliminary impressions are taken only in emergencies
• D. Final impressions are less accurate

Answer: (B)

The distinction between preliminary and final impressions lies primarily in their purpose and the level of detail they capture. Final impressions are designed to be highly accurate and are used to create definitive restorations, such as crowns, bridges, and dentures. These impressions capture the precise anatomy of the teeth and surrounding structures, ensuring that any dental appliances made will fit well and function properly.

In contrast, preliminary impressions are typically less detailed and are often used for making diagnostic casts, treatment planning, or as a starting point for further procedures. While they serve important roles in the dental process, they do not provide the same level of fidelity required for producing restorations. Therefore, the correctness of the answer is rooted in understanding that final impressions are specifically used for the fabrication of restorations, making them critical to the success of dental treatments.