Rebase

A rebase is a procedure that replaces the entire acrylic base of a denture while keeping the existing prosthetic teeth in their current positions. Unlike a reline, which only resurfaces the tissue-fitting side, a rebase involves replacing all of the pink acrylic material — both the polished outer surface and the intaglio (tissue) surface.

When Rebasing Is Appropriate

Rebasing is more extensive than relining and is typically recommended when:

• The base acrylic is worn or aged — After years of use, denture acrylic can become porous, stained, or weakened. A rebase replaces this compromised material with fresh acrylic.
• The denture has been repaired multiple times — Repeated repairs can leave seams, weak points, and discoloration. Rebasing gives the denture a clean start.
• The base is structurally unsound — Hairline cracks, crazing (fine surface fractures), or areas of thinning compromise the denture’s integrity.
• The teeth are still in good condition — If the prosthetic teeth show acceptable wear and the patient is satisfied with their appearance and arrangement, rebasing preserves the teeth while giving them a new foundation.

The Rebase Process

1. The dentist takes a new impression inside the existing denture
2. The denture and impression are sent to the lab
3. The technician carefully separates the teeth from the old acrylic base
4. New acrylic is processed around the teeth in their existing positions using the new impression to establish the tissue-fitting surface
5. The denture is finished, polished, and returned

Rebase vs. Reline

The key distinction: a reline adds new material only to the tissue surface, leaving the rest of the denture untouched. A rebase replaces all of the acrylic. Rebasing takes longer and costs more, but it addresses structural issues that relining cannot.

Rebase vs. New Denture

A rebase is significantly less expensive than fabricating a new denture and preserves the tooth arrangement the patient is accustomed to. However, if the teeth themselves are severely worn, chipped, or the wrong shade, a new denture may be the better investment.