Denture wearers often find that their removable replacements for missing teeth require periodic adjustment to maintain a comfortable and secure fit. This procedure is called a reline, which involves resurfacing the part of the denture that rests against the gum tissue. A hard reline is a specific type of adjustment that uses durable, rigid material to restore the intimate contact between the denture base and the oral tissues. Understanding this procedure helps people with loose dentures find a long-lasting solution for improved comfort and function.
The Purpose of a Hard Reline
A hard reline provides a definitive, long-term solution for dentures that have become loose over time. The process involves adding a new layer of a hard, non-resilient acrylic material to the tissue-fitting surface of the existing denture base. This new material, typically a form of polymethyl methacrylate (PMMA), is similar to the original denture material and is highly durable. The goal is to perfectly match the current contours of the person’s mouth, thereby closing the gaps that developed between the denture and the gums. A properly executed hard reline restores the denture’s stability and retention.
Why Denture Fit Changes Over Time
The need for a reline stems from the body’s natural response to tooth loss, a process known as alveolar bone resorption. Once teeth are removed, the jawbone structure that supported them begins to shrink and change shape. This continuous, irreversible phenomenon causes the underlying bony ridge to diminish. The denture base, which was initially custom-fit to the jaw, eventually no longer corresponds to the altered gum and bone contours. This discrepancy leads to common problems such as the denture slipping, poor stability, and the development of painful sore spots.
The Clinical Process of a Hard Reline
The highest-quality hard relines are typically lab-processed to ensure the most precise and durable outcome. The procedure begins with the dentist preparing the existing denture by removing a thin layer of old acrylic from the internal surface to create space for the new material. Next, a special putty-like impression material (a wash impression) is placed inside the prepared denture and seated in the patient’s mouth to capture the current tissue anatomy. The denture is then sent to a dental laboratory where the impression material is replaced with rigid acrylic resin, which is cured under heat and pressure to achieve maximum strength. This laboratory process usually means the patient will be without their denture for 24 to 48 hours until the final fitting and adjustment.
Hard Reline vs. Soft Reline
Hard and soft relines differ significantly in their material composition, intended function, and longevity. A hard reline uses a rigid, acrylic-based material designed for a stable, long-term fit, often lasting two to five years. This is the preferred choice when the gum tissues are healthy and jawbone changes have stabilized. In contrast, a soft reline uses a pliable, rubbery material, often silicone-based, to create a cushioned surface against the gums. Soft relines are temporary solutions, frequently used to provide immediate relief for chronic sore spots or to condition irritated tissue, but they typically last only 12 to 18 months.