Rebase

A denture rebase is a laboratory procedure in which the entire acrylic resin base of an existing denture is removed and replaced with new base material while preserving the original denture teeth in their established positions. The process involves removing all existing pink acrylic from around the teeth, taking a new impression of the patient's oral tissues using the denture teeth as a tray, and then processing new acrylic around the repositioned teeth to create a fresh base that conforms accurately to the current tissue contours. Rebasing is indicated when the base material has become structurally compromised through cracking, porosity, discoloration, or accumulated wear, but the artificial teeth remain in acceptable condition and the occlusal relationships are still clinically sound.

Rebasing is a more extensive procedure than relining and should not be confused with it in either clinical documentation or billing submissions. A reline adds a new layer of material to the tissue-contacting surface of the existing base to improve adaptation, while a rebase replaces the entire base structure. The clinical decision between reline and rebase depends on the condition of the existing base material. When the base is structurally intact but no longer fits well, a reline is appropriate. When the base itself is degraded, a rebase provides a more durable and hygienic result at a lower cost than fabricating a completely new denture. Rebasing requires the patient to be without the denture for the laboratory processing period, typically one to three days, which must be communicated during treatment planning.

The CDT coding system provides separate codes for complete and partial denture rebases, and these codes are distinct from both reline codes and new denture fabrication codes. Submitting the appropriate rebase code ensures the practice receives the correct reimbursement for the level of work performed. Insurance plans commonly cover rebasing after a minimum time period following initial denture delivery, typically six months to one year, and may impose frequency limitations of one rebase per denture within a defined benefit period. Documentation should include the reason the rebase was necessary, the condition of the existing base, confirmation that the teeth and occlusion were acceptable, and the type of base material used. This documentation supports the claim and differentiates the procedure from a reline in the event of a payer audit.