Which material is commonly used as a final impression for fixed restorations?

Which material is commonly used as a final impression for fixed restorations?

• A. Polyvinyl siloxane (PVS)
• B. Alginate
• C. Polyether
• D. Zinc oxide-eugenol

Answer: (A)

Capturing an accurate final impression for a fixed restoration requires a material that remains dimensionally stable after removal and during any storage, while also providing strong tear resistance and excellent detail reproduction. Polyvinyl siloxane delivers these qualities: it has superb dimensional stability, so the impression doesn’t distort as it sits or as it’s poured, and its tear strength helps prevent ripping when removing it from the prepared tooth margins. It also records fine details clearly and can be poured multiple times without losing accuracy, which is essential for precise crown and bridge fabrication. Alginate tends to shrink or distort more over time and tears more easily, so it isn’t ideal for final impressions of fixed restorations. Polyether is accurate and hydrophilic, which helps in moist mouths, but it can be stiffer and harder to handle, sometimes complicating patient comfort and margin capture. Zinc oxide-eugenol isn’t used as a final impression material for fixed restorations because it doesn’t provide the needed surface detail or long-term dimensional stability.

Capturing an accurate final impression for a fixed restoration requires a material that remains dimensionally stable after removal and during any storage, while also providing strong tear resistance and excellent detail reproduction. Polyvinyl siloxane delivers these qualities: it has superb dimensional stability, so the impression doesn’t distort as it sits or as it’s poured, and its tear strength helps prevent ripping when removing it from the prepared tooth margins. It also records fine details clearly and can be poured multiple times without losing accuracy, which is essential for precise crown and bridge fabrication.

Alginate tends to shrink or distort more over time and tears more easily, so it isn’t ideal for final impressions of fixed restorations. Polyether is accurate and hydrophilic, which helps in moist mouths, but it can be stiffer and harder to handle, sometimes complicating patient comfort and margin capture. Zinc oxide-eugenol isn’t used as a final impression material for fixed restorations because it doesn’t provide the needed surface detail or long-term dimensional stability.