Dentures are removable prosthetic devices that replace missing teeth and surrounding gum tissue, restoring a patient’s ability to eat, speak, and smile. Although the acrylic and resin materials of the denture remain stable, the mouth underneath constantly changes. After natural teeth are lost, the jawbone and gum tissue undergo resorption, causing the underlying bone to shrink and soft tissue contours to change over time. This dynamic process causes the once-precise fit of the denture to become loose, leading to discomfort and functional issues that require adjustment.
When Dentures Require Attention
Patients typically notice their dentures need attention when they experience specific, irritating symptoms. Sore spots, often painful areas or ulcers on the gums, are a common sign that the denture is rubbing against the tissue due to an uneven fit. Other indications include difficulty chewing or speaking, a noticeable clicking sound, or the denture shifting or slipping out of place during function. Ignoring these signs can lead to complications, such as accelerated jawbone loss or chronic irritation and infection of the oral tissues.
The dentist’s initial step is a precise diagnostic process to locate the exact points of excessive pressure. A common tool for this is Pressure Indicating Paste (PIP), a non-setting material applied to the internal surface of the denture. When the denture is seated and light pressure is applied, the paste is wiped away or “smudged” in areas of intimate contact. A spot completely denuded of the paste indicates a high-pressure point, allowing the dentist to pinpoint the problem area corresponding to the patient’s discomfort.
Localized Chairside Adjustments
Once pressure points are identified using diagnostic paste, the dentist performs a localized chairside adjustment to relieve the impingement. This involves using specialized rotary instruments, such as carbide burs or abrasive stones, to precisely remove small amounts of the denture’s acrylic base. The material is reduced only in the marked areas where the PIP was wiped away, often overextended flanges or sharp projections. The goal is to smooth the denture’s surface, allowing it to conform better to the gum tissue without causing trauma.
After relieving the pressure points, the dentist assesses and adjusts the patient’s bite, or occlusion. Ill-fitting dentures can cause uneven contact between the upper and lower teeth, leading to tipping or loosening during chewing. Articulating paper, a thin strip coated with colored pigment, is placed between the teeth to mark contact areas when the patient bites down. High spots showing a heavy, dark mark are then ground down using fine burs to create a balanced and stable bite, distributing chewing forces evenly.
The final step in a localized adjustment is ensuring the altered areas are smooth and comfortable. Surfaces that were ground down are polished to prevent rough edges from irritating the tongue or cheeks. This finishing process prevents a rough surface from harboring bacteria or causing new sore spots. The process of diagnosis, material reduction, and polishing is often repeated until the patient reports the pressure is relieved and the fit feels stable.
Restoring Overall Fit: Relining and Rebasing
When localized chairside adjustments are insufficient, the entire foundation of the denture must be addressed through relining or rebasing. Relining is the process of adding new acrylic base material to the tissue-fitting surface, or intaglio, of the existing denture to compensate for minor gum and bone shrinkage. This procedure restores intimate contact between the denture and oral tissues, improving stability and suction without altering the tooth position or external shape. A hard reline uses durable acrylic and is typically performed in a dental laboratory, while a soft reline uses a more pliable material for cushioning, often for patients with chronic sore spots.
Rebasing is a more extensive procedure that replaces the entire pink acrylic base of the denture while preserving the existing artificial teeth. This is necessary when the denture base is cracked, weakened, structurally compromised, or when oral changes are too significant for a reline to correct. Rebasing provides a completely new, strong foundation, custom-fabricated to the latest impression of the patient’s oral tissues. Due to the difference in scope, a reline can sometimes be completed chairside, but a rebase almost always requires the denture to be sent to a dental laboratory for several days.
Ensuring Long-Term Comfort and Stability
Following a denture adjustment, a follow-up visit is typically scheduled within 24 to 48 hours to check for new areas of irritation. Because the pressure distribution has changed, the patient may develop new sore spots requiring minor, subsequent adjustments. Patients must wear the denture for several hours before this appointment so the dentist can accurately identify any new pressure areas.
Long-term stability relies on proper daily cleaning and professional oversight. Dentures should be brushed daily with a soft-bristled brush and a non-abrasive cleanser, avoiding regular toothpaste which can scratch the acrylic. They should also be removed for at least six hours daily, usually overnight, and soaked in water or a cleaning solution to give the gum tissues a rest and prevent warping. Dentists recommend professional check-ups at least once or twice a year to monitor the fit and the health of the underlying tissues. Regular evaluations help determine the need for preventative relining, typically recommended every few years to maintain an optimal fit and prevent accelerated bone loss.