ANSWERS

What is the difference between a hard reline and a soft reline?

A hard reline resurfaces a denture's tissue side with rigid acrylic that bonds permanently to the base, typically lasting 3 to 5 years. A soft reline uses a pliable silicone or resilient polymer for patients with sore, thin, or bony ridges, lasting 12 to 24 months. Hard relines restore fit.

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Why it works this way

The core material difference

Hard relines use heat-cured or chairside acrylic that chemically bonds to the existing denture base. Once cured, the new tissue surface behaves identically to the original PMMA: rigid, polishable, dimensionally stable. Soft relines use a resilient liner, typically a silicone elastomer or a plasticized acrylic, that retains permanent cushioning. The Shore A hardness gap tells the story. Hard acrylic measures around 85 to 90 Shore A. Soft liners run 20 to 50 Shore A depending on formulation.

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Can a soft reline be converted to a hard reline later?

Yes. When the soft liner reaches end of life at 12 to 24 months, the liner is removed down to the original base and a hard reline is processed in its place, assuming tissue tolerance has improved. This is common for immediate denture patients: soft liner during the 6 to 12 month healing and remodeling window, then hard reline once the ridge stabilizes. The denture base itself is not replaced unless the acrylic shows fatigue cracks or stain penetration.

Is a chairside reline as durable as a lab-processed reline?

No. Chairside hard reline materials are self-curing acrylics designed for same-visit turnaround, which means higher residual monomer, more porosity, and weaker bond strength to the original base. Lab-processed relines use heat-cured acrylic under pressure, producing a denser, more color-stable, and longer-lasting result. The clinical tradeoff is 3 business days of lab time against roughly double the service life. For patients with sensitivity to residual monomer, lab processing is the safer route.

When should a reline be declined in favor of a new denture?

Reline a denture only if the occlusion, vertical dimension, tooth wear, and base integrity are still acceptable. Decline the reline and recommend a new denture when teeth show through-wear into the acrylic, when vertical dimension has collapsed more than 2mm, when the base has fatigue cracks or repeated repairs, or when the patient has had the denture longer than 7 to 8 years. A reline on a worn-out denture buys 6 months and a callback, not a solution.

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This answer is one piece of a larger workflow. The pillar page covers materials, turnaround, and how we build the case to your specification.

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