Denture wearers often experience a gradual change in how their prosthetic fits over time, leading to looseness, discomfort, or instability. This shift occurs because the underlying bone and gum tissues naturally change shape after tooth loss, causing the denture to no longer conform to the mouth’s contours. When a denture becomes ill-fitting, the standard solution to restore stability and comfort is a procedure called relining. This process adjusts the fit of the existing prosthetic, allowing it to function correctly once more.
Why Denture Fit Changes Over Time
The primary reason a secure denture fit deteriorates is a biological process known as alveolar ridge resorption. This phenomenon is the slow, continuous shrinkage of the jawbone that previously anchored the natural teeth. When a tooth root is removed, the bone it stimulated no longer receives the necessary pressure signals, causing the body to resorb the bone tissue over time.
This loss of bone density causes the jawbone structure to become progressively thinner and shorter, fundamentally changing the shape of the mouth’s foundation. Since dentures rest directly on the gum tissue and underlying bone, any change in this foundation means the denture’s custom-made base no longer matches the oral anatomy. Gum tissue can also become thinner or softer due to the constant pressure of a loose denture, further contributing to the poor fit and resulting in slipping and shifting.
Understanding Denture Relining
Denture relining is a focused procedure that modifies the tissue-fitting surface of an existing denture to match the current contours of the gums and jawbone. It involves adding a new base material, typically a type of acrylic resin, to the inside of the denture shell. This addition effectively fills the gap created by the changes in the mouth, restoring the tight seal needed for proper suction and stability.
The core purpose of relining is to enhance the comfort and function of the prosthetic without altering its appearance. Importantly, relining only addresses the fit against the gums; it does not change the position of the artificial teeth or the overall vertical dimension of the denture. This differs from re-basing, which is a more extensive process that replaces the entire acrylic base material while retaining the original teeth. A successful reline significantly improves stability, reduces movement during chewing or speaking, and minimizes the irritation that loose dentures can cause.
The Different Types of Relines
Dental professionals classify relines based on the material used and the duration of the solution, with three main types available.
Hard Reline
The Hard Reline is the most durable and long-lasting option, using a rigid acrylic material similar to the original denture base. This type often requires the denture to be sent to a dental laboratory for processing, ensuring a highly accurate and stable fit that can last for two to four years. It provides maximum stability and is the preferred choice for patients with healthy gum tissue seeking a long-term solution.
Soft Reline
The Soft Reline utilizes a pliable, cushion-like material, such as medical-grade silicone or soft polymer. This material remains flexible after curing and is recommended for patients who have sensitive gums, severely resorbed ridges, or chronic sore spots. While a soft reline offers immediate comfort, the material is less durable and typically requires replacement every one to two years.
Temporary Reline
The Temporary Reline, also known as tissue conditioning, uses a soft, medicated material applied directly in the dental office. This reline is not a long-term solution but is used therapeutically to allow inflamed or swollen gum tissue to heal before a permanent hard reline can be performed. By providing a temporary, cushioned fit, the material helps irritated tissues return to a healthy state, ensuring a more accurate impression for the final reline.
What to Expect During the Reline Procedure
The reline process begins with an examination of the mouth and the denture to assess the fit issue and identify any irritation. For either a hard or soft reline, a new impression of the patient’s gum tissues is taken directly inside the existing prosthetic. The dentist places impression material into the denture’s base and then has the patient bite down gently to capture the precise contours of the current oral structure.
If an in-office soft reline is performed, the material is applied and cures while the patient waits, meaning the denture is returned the same day, often within an hour. For a lab-processed hard reline, the denture is sent away for the new acrylic to be cured and finished, which can take a few days. During this time, the patient may be without their denture, or a temporary prosthetic may be provided. Once returned, the dentist performs a final fitting, making minor adjustments to ensure the bite is comfortable and the fit is secure.