When Should a Denture Be Replaced?
There is no specifically agreed-upon chronological answer by dentists to "When should a denture be replaced?" There are instances where dentures have been replaced after 1 year or less, and on the opposite side of the spectrum, there are people who have worn the same dentures for 25 or more years. These ranges obviously are extremes.
However, on average, dentists seem to be replacing dentures somewhere between four to eight years. This would seem to imply that the average denture fabricated from contemporary biomaterials will wear out and deteriorate within that time and/or the average denture patient's jaws have changed so much that a new denture must be redone.
Each individual's denture needs are different. There are some factors that a licensed dentist takes into consideration when evaluating the need to replace dentures.
Denture Longevity Considerations
Lost vertical dimension:
The proper linear distance relationship between the upper and lower jaws is called vertical dimension. This is unique for each individual.
As one's jaw changes and the ridges upon which dentures rest shrink, a denture becomes loose and vertical dimension begins to change (the vertical dimension is said to be lost by a certain linear measurement unit such as millimeters). Additional plastic (acrylic resin) is added to the inside of a loosening denture (called relining a denture) to stabilize it by reducing looseness caused from jaw shrinkage. However, relining does not restore vertical dimension in an accurate way.
The current position held by most dentists is that when vertical dimension has been lost by three millimeters or more, a new denture should be fabricated in order to restore vertical dimension and maintain functional health.
There are individuals who have worn the same denture for extended periods with considerable loss of vertical dimension over time. Since vertical dimension loss is a slow, but nevertheless progressive, process, they have gradually adapted to a continually increasing closed bite position. These individuals often have a sunken facial appearance and usually appear much older than their chronological age.
Functioning with an abnormal vertical dimension may eventually result in alterations of the temporomandibular joints (TMJ, the jaw joint located in front of the ears). This can lead to significant pain and difficulty with effective eating and even the jaw motions involved with speech. It frequently becomes quite difficult, if not impossible, to restore such individual's proper vertical dimension and chewing efficiency by relining and repairing this older denture.
Tooth wear:
Aside from impaired ability to chew effectively, excess tooth wear will adversely affect esthetics and cause other problems associated with lost vertical dimension, as described above. While porcelain denture teeth will wear at a slower rate than plastic teeth, they nevertheless will wear and are more susceptible to chipping and cracking. Multiple cracked teeth will need to be replaced.
Deterioration: While the biomaterials used by dentists to fabricate dentures today are quite durable, they still deteriorate and exhibit dimensional change over time -- no longer fitting properly, even after relining.
Aging plastic looses its natural appearance and texture, and coloration fades, making dentures look quite artificial.
Deteriorating plastic also makes it easier for dentures to become excessively contaminated with microorganisms. This contributes to mouth irritation and bad taste, and socially unacceptable odors will develop that no amount of denture cleaning will seem to eliminate.
Keeping regular dental check-ups with your dentist so that one's dentures, soft tissues, and jawbone may be checked is essential to extending the life of a denture and maintaining oral health.
by Joseph J. Massad, D.D.S.
+Jim Du Molin is a leading Internet search expert helping individuals and families connect with the right dentist in their area. Visit his author page.
The Effects of Aging and Wear on the Mouth
Tooth loss is not part of the normal aging process. In fact, tooth loss is declining among older adults. Aging does not cause oral diseases, yet oral diseases such as tooth loss are more prevalent with age due to changes in the oral soft tissues, a depression of the immune system, an increase in the number of systemic diseases, a decreased ability to perform adequate oral hygiene and self care secondary to stroke, arthritis, Parkinson's disease, dementia, or Alzheimer's disease, and dry mouth due to greater use of prescription and over-the-counter medications.
With age, teeth become less white and more brittle; however, oral hygiene habits and use of tobacco, coffee, and tea also will affect tooth color. Teeth also can darken or yellow due to the thickening of the underlying tooth structure (dentin). Brittle teeth tend to be susceptible to cracks, fractures, and shearing. Over the years, the enamel layer (outer tooth layer) is subjected to wear due to chewing, grinding, and ingestion of acidic foods. In severe cases, the enamel is completely worn away and the underlying dentin is worn down as well. Inside the tooth (pulp), the number of blood vessels and cells decrease and fibroses increase with age; thus, capacity to respond to trauma may also decrease.
The fiber content and number of blood vessels of the periodontal (gum) tissues decrease with age. However, periodontal disease represents a pathologic or disease change and is not due to just age. The loss of bone and gum attachment (receded gums) associated with periodontal disease is collective and therefore greater in older adults. An outcome of periodontal disease is exposed root surfaces. Exposure of the root in older people probably gave rise to the term "long in tooth". Oral hygiene practices and certain medications affect the health of gum tissue. Receded gums and exposed root surfaces put older adults at high risk for dental decay (root caries) on the relatively soft root surfaces. Dental caries on root surfaces is a disease that is common among older adults. Dry mouth and a diet high in sugars and fermentable carbohydrates greatly increase the risk for root caries. Dental caries are a major cause of tooth loss in older adults.
Studies show some reduced chewing effectiveness, decreased tongue strength, and increased swallowing time with age; however, the studies do not indicate that there is any real change in the ability to swallow with age.
The number of cells that produce saliva decrease with age. However, healthy, unmedicated older adults do not have reduced saliva flow. This is because the salivary glands have a high reserve capacity. Usually when a decrease in saliva flow is noted, it is associated with medication use, illness, medical conditions, or their treatment. The number of taste buds do not appear to change with older age; thus, the ability to taste does not change significantly with age. However, smell decreases with age. Since the ability to taste is closely related to smell, taste perception may be altered in older adults.
Soft tissues of the mouth become thinner and lose elasticity with age. Soft tissue lesions are more common in older adults and tooth loss may occur. Chronic inflammation such as candidiasis (fungus growth) and denture irritation also occurs more often. Wound healing is decreased due to reduced vascularity (blood flow to the area) and immune response with age.
Oral and oropharyngeal cancer is the most serious disease associated with age. Oral and oropharyngeal cancer lesions usually are not painful. Oral and pharyngeal cancer may appear as a red or white patch, a sore or ulceration, or a lump or bump that does not heal within two weeks. Swollen lymph nodes of the neck, difficulty swallowing and speaking, and voice changes also may be signs and symptoms of oral and oropharyngeal cancer. The risk for oral and oral pharyngeal cancer increases with age, use of all forms of tobacco, frequent alcohol use, and exposure to sunlight (for lip cancer). See a dentist if any signs or symptoms of oral and pharyngeal cancer are present.
+Jim Du Molin is a leading Internet search expert helping individuals and families connect with the right dentist in their area. Visit his author page.