Dentures are removable prosthetic devices that replace missing teeth and surrounding tissues, restoring appearance and function. Although constructed from durable materials like acrylic resin, dentures inevitably wear out. This wear results from constant mechanical forces, the chemical environment of the mouth, and natural biological changes over time.
The Typical Lifespan of Dentures
The functional life of a denture is not indefinite. Conventional full dentures typically last five to ten years of regular use, while partial dentures may last slightly longer. This timeframe reflects the point when material fatigue or oral changes commonly necessitate replacement.
Material fatigue occurs naturally from the daily stress of chewing and speaking, slowly degrading the acrylic base and artificial teeth. Although regular adjustments and relines can temporarily extend use, they cannot halt the underlying aging process that requires eventual replacement.
Factors Accelerating Denture Deterioration
The rate at which a denture wears out can be significantly accelerated by a combination of physical, chemical, and biological factors.
Mechanical Factors
Repetitive, high-impact forces generated during chewing (occlusal stress) cause artificial teeth to slowly grind down, altering the bite alignment. Abrasive cleaning methods, such as using stiff brushes, can scratch the acrylic surface, creating microscopic imperfections. These defects weaken the material and make it more susceptible to staining and fracture.
Chemical Factors
The denture material is constantly exposed to the mouth’s fluctuating environment, including saliva and various foods. Acrylic resin is porous and absorbs liquids, which can induce internal strains and chemical breakdown. Harsh chemicals like bleach can further degrade the resin, causing it to become brittle and dull.
Biological Factors
The most significant factor is alveolar ridge resorption that follows tooth loss. Without stimulation from natural tooth roots, the jawbone beneath the gums shrinks and changes shape. This structural change causes the denture base to become ill-fitting, placing uneven stress on the appliance and effectively wearing out the fit.
Recognizable Signs That Dentures Are Worn
Patients should look for several signs indicating their prosthetic appliance is nearing the end of its useful life. Functionally, a worn denture often loses stability, resulting in clicking or whistling sounds during speech. The appliance may shift or wobble while eating, making it difficult to chew and increasing the need for denture adhesives.
Aesthetic changes are another clear indicator. The artificial teeth may exhibit visible signs of wear, such as flattened biting surfaces, chips, or small cracks. The acrylic base can become deeply stained, develop a dull color, or become porous, resisting normal cleaning methods.
Fit issues manifest as discomfort, soreness, or persistent pressure points on the gums. If the denture is loose, food particles can become trapped underneath the base, leading to chronic irritation. A porous appliance can also harbor bacteria, sometimes causing persistent bad breath.
Health Consequences of Using Old Dentures
Continuing to wear an ill-fitting or worn denture can lead to negative health consequences that extend beyond simple discomfort. The uneven pressure distribution from a loose-fitting appliance can significantly accelerate the rate of jawbone resorption. This accelerated bone loss further compounds the fit problem, creating a cycle that can eventually make it difficult or impossible to wear any conventional denture.
Chronic irritation from a shifting appliance can cause inflammation and the development of painful oral lesions, ulcers, or pressure sores on the soft tissues. A denture that has become porous or constantly traps food debris can become a breeding ground for microorganisms. This often leads to fungal infections like denture stomatitis, which causes redness under the denture, or angular cheilitis, an inflammatory condition that results in cracked and irritated corners of the mouth.
Difficulty chewing efficiently with worn dentures can also have systemic effects on the body. An inability to properly break down food can lead to digestive issues and limit a person’s diet to softer foods. This restriction can result in the inadequate intake of essential nutrients, potentially contributing to poor overall health and nutritional deficiencies.