Which procedure replaces an existing denture base with a new hard acrylic base?

• A. Rebase
• B. Impression Materials
• C. Gypsums
• D. 5-7 years

Answer: (A)

Replacing the entire denture base with a new hard acrylic base is called a rebase. This procedure is used when the base itself is worn, cracked, or otherwise unsuitable, and simply resurfacing the tissue side isn’t enough to restore fit or function. In a rebase, the teeth are typically kept in place while the old base resin is removed and a new base is formed from impression material that captures the anatomy accurately, then processed and finished to restore proper occlusion and stability.

Impression materials and gypsums aren’t procedures themselves; they’re materials used during the process—for making impressions and models—while 5-7 years is just a time interval and not a procedure.