Dentures are removable replacements for missing teeth designed to restore function and appearance. Stability depends on individual factors, the type of denture worn, and maintenance. While a well-fitting denture can be secure, many people require assistance from products or professional adjustments. Proactive measures are necessary to keep the prosthetic from shifting or dislodging, especially during eating or speaking.
Factors Determining Denture Stability
The primary support for a traditional denture comes from the underlying anatomical structure of the mouth. The alveolar ridge, the bone structure that previously held the natural teeth, provides the foundation upon which the denture rests. A taller, broader, and more square-shaped ridge offers a better base for stability than a narrow or flat one.
For upper dentures, retention is largely achieved through a seal that creates a vacuum against the roof of the mouth. If the denture base extends properly, this seal provides substantial resistance to dislodgement. Lower dentures have less surface area and must contend with a moving tongue and cheek muscles, making them naturally less stable than their upper counterparts.
The composition and quantity of saliva also play a role in how well a denture stays put. Saliva acts as a thin liquid layer between the denture and the gum tissue, helping to maintain the suction seal. Too little saliva, often caused by medications, can break the seal and lead to dryness, while excessive, thin saliva can also make it difficult to establish a consistent seal.
Over time, the shape of the jawbone changes due to residual ridge resorption. Once teeth are removed, the lack of stimulation causes the alveolar bone to shrink progressively, an irreversible process. As the underlying bone structure diminishes, the once-snug denture becomes loose and ill-fitting, leading to poor retention and the need for adjustment or replacement. This bone loss occurs more rapidly in the lower jaw compared to the upper jaw.
Methods to Enhance Denture Retention
When dentures begin to feel loose due to normal changes in the mouth, several non-surgical steps can be taken to improve their fit and stability. Denture adhesives are a common and immediate solution, working by filling the microscopic gaps between the denture base and the gum tissue to enhance the seal.
Adhesive creams are the most common type, providing a strong, all-day hold and often creating a cushioning layer to reduce sore spots. Adhesive powders are activated by moisture and are generally easier to apply, leading to less mess, though they might offer a lighter hold. Pre-cut adhesive strips offer a convenient, mess-free option with a secure hold, as they contain a pre-measured amount of material.
Regular professional adjustments are necessary to maintain the long-term fit. Relining involves adding new material to the internal surface of the denture to conform it to the current shape of the gum tissues. Rebasing is a more extensive process that replaces the entire acrylic base while keeping the original prosthetic teeth. Both procedures compensate for minor bone changes and restore the denture’s original fit, generally recommended every few years.
Proper daily care prevents material breakdown that can compromise fit. Dentures must be cleaned daily to prevent the buildup of plaque and tartar. They should be stored properly when not worn, often in water or a soaking solution, which prevents the acrylic material from drying out and warping.
Permanent Solutions for Unstable Dentures
For individuals experiencing severe instability or who cannot tolerate adhesives, dental implants offer a long-term solution. These are small titanium posts surgically placed into the jawbone, where they fuse with the bone to act as secure anchors. Implants prevent the continued bone loss associated with traditional dentures by providing necessary stimulation to the jawbone.
One implant-supported option is the “snap-in” denture, also known as an overdenture. This removable prosthetic uses special attachments that clip onto two to four implants per arch. While still removable for cleaning, these overdentures offer better retention and stability than conventional dentures, eliminating the need for daily adhesives.
For stability and a feel most similar to natural teeth, fixed implant-supported dentures are available. Systems like All-on-4 use a small number of precisely placed implants to permanently secure a full set of prosthetic teeth. These restorations are non-removable by the patient and provide high chewing efficiency, as they are securely screwed onto the implants and only a dentist can take them out.