What is the purpose of border molding in impression tray setup?

• A. To shape the impression tray border to capture a precise impression and adequate tissue coverage.
• B. To determine occlusion after the impression.
• C. To color-code the tray.
• D. To sterilize the tray before use.

Answer: (A)

Border molding shapes the edge of the impression tray so the final impression records an accurate peripheral contour. By molding the borders to follow the depth of the vestibule and the mucobuccal folds, you ensure the tray extends adequately and the tissues are captured in a functional position. This provides proper tissue coverage, prevents distortion or voids at the borders, and leaves space for the impression material to record the margins without tearing. In short, it defines the tray borders to produce a precise, stable impression that accurately reflects the surrounding soft tissue. The other options aren’t related to this step—they address occlusion, tray color-coding, or sterilization, not border contouring.