The fit of a denture is not permanent because the tissues in the mouth constantly change. When a denture begins to feel loose, slip while speaking or eating, or cause discomfort, a reline becomes necessary to restore its function and comfort. The reline process involves adding a new layer of material to the fitting surface of the denture base, which is the part that rests directly on the gums. This procedure is a common form of maintenance that adjusts the denture to the current contours of the mouth, often avoiding the need for a complete replacement.
Understanding Denture Relines and Their Purpose
The need for denture relines stems from a natural biological process known as alveolar bone resorption. When natural teeth are lost, the jawbone that once supported them no longer receives the necessary stimulation, causing the bone tissue to gradually shrink and change shape over time. This process alters the underlying structure of the jaw and the soft tissue contours, meaning a denture that initially fit perfectly will inevitably become loose and unstable.
A denture reline physically compensates for the void spaces created by this jaw shrinkage. The procedure involves taking an impression of the gum ridge and applying a new lining material to the denture surface. This resurfacing fills the developed gaps, restoring the snug fit and proper suction. A secure fit prevents movement, which reduces irritation, sore spots, and the potential for accelerated bone loss caused by an unstable prosthesis.
The Expected Lifespan of Different Reline Types
The duration a denture reline lasts depends directly on the type of material used and the method of application. Dentists utilize three primary types of relines, each designed for a specific purpose and offering a distinct service life. The choice of reline type is based on the condition of the oral tissues and the desired permanence of the fix.
Hard Reline (Lab Processed)
A hard reline is the most durable and long-lasting solution, typically lasting between two and four years. This type uses a hard acrylic resin, the same material used to construct the original denture base. The process usually requires sending the denture to a dental laboratory for processing, ensuring a precise bond to the existing material. Hard relines are recommended when the oral tissues are healthy and the denture is in good structural condition.
Soft Reline
Soft relines use a pliable, cushioned material, often a medical-grade soft polymer, that acts as a shock absorber between the hard denture base and the gums. This type provides a gentler fit and is recommended for patients with sensitive gums, chronic sore spots, or those new to wearing dentures. Because the material is softer and more porous, it tends to break down, harden, or absorb odors over time, giving it a shorter lifespan of approximately one to two years.
Temporary/Conditioning Reline
Temporary relines are short-term solutions designed to last only a few weeks to a few months. They utilize a conditioning material intended to calm and heal inflamed or irritated gum tissues before a definitive hard reline or a new denture can be made. These relines are generally applied chairside in a single visit and are not meant for long-term use. Once the underlying tissue inflammation has resolved, the patient must return for a more permanent relining procedure.
Factors Influencing Reline Duration and Maintenance
The actual lifespan of any reline can vary significantly based on individual factors and daily maintenance practices. Patient hygiene is a major factor, as soft reline materials are particularly prone to absorbing moisture and accumulating yeast or bacteria. Thorough and gentle daily cleaning is necessary to prevent the material from deteriorating prematurely or causing tissue irritation.
The most influential biological factor is the individual rate of bone resorption in the jaw. This bone loss is an ongoing process unique to every person, meaning some wearers will experience a change in fit more quickly than others. Significant weight loss can also alter the facial and gum tissue volume, accelerating the need for a new reline or a complete denture adjustment. Regular professional monitoring is necessary to ensure the denture continues to fit correctly and to check the health of the oral tissues. Dentures themselves generally need replacement every five to seven years, as a reline only addresses the fit against the gums, not the wear and tear on the artificial teeth or the overall base structure.