tooth decay / cavities / dental caries

Adults: The cavity prone years.

Adults can, even after a long period of having little or no difficulties with tooth decay, enter a period where cavities become a significant problem.

As the contents of this page describe, this recurrence of "cavity prone" years for adults is often associated with: 1) Changes that take place with a person's saliva (such as xerostomia).   2) The presence of gum recession.

Gum recession and tooth decay formation on root surfaces.

A tooth's enamel covering ends right about at that level where the tooth's gum line was positioned when the tooth first came in. This enamel-covered part of a tooth is termed its "crown."

All of the tooth that lies below the crown (meaning that portion of the tooth encased in gum tissue and bone) is classified as a tooth's root.

Tooth roots are "softer" than enamel.

The root portion of a tooth is not composed of, or covered over by, dental enamel. Instead it is chiefly composed of another mineralized tooth tissue called dentin.

And since dentin contains less mineral content than enamel (it's less "hard"), it is more easily, and quickly, damaged by the cavity-forming demineralization process.

Gum recession exposes a tooth's roots.

If gum recession occurs, a tooth's root will be exposed (meaning they are no longer fully covered over by gum tissue and bone).

Because the root surface of a tooth is relatively "soft" (as compared to dental enamel). And because, due to their location, exposed root surfaces can be difficult to effectively clean (and therefore dental plaque is continually present). Decay can form on them relatively easily, thus putting a person through another period of cavity-prone years.

What can cause gum recession?

Gum recession can be due to many factors. And any recession that does occur can be localized to just a few teeth, or else be a generalized condition.

Many times, as a person passes through the decades of life, multiple factors have come into play each of which have added to, cumulatively, to the amount of gum recession that a person has. This is one reason why gum recession is typically associated with adulthood, especially the senior years.

Some of the conditions and habits that can cause gum recession are:

• Gum disease (periodontal disease) and those procedures required for its treatment can result in gum recession. Gum disease is typically associated with the persistent accumulation of dental plaque (due to ineffective brushing and flossing habits).
• Improper, or over zealous, tooth brushing can cause gum recession. Brushing too forcefully, or brushing back and forth with a "sawing" motion, can cause damage to occur. So can brushing with a toothbrush whose bristles are too stiff.
• Bruxism (tooth clenching and grinding) can produce changes in teeth that result in their gum line receding.

What role does saliva play in preventing tooth decay?

Saliva plays a very important role in process of fighting tooth decay. Here is a list of some of the benefits that it provides:

• Saliva contains buffering agents that help to neutralize the acids that cause tooth demineralization.
• Saliva contains the minerals that must be present for the tooth remineralization process to occur.
• Saliva contains antibacterial agents that can help to inhibit the growth of oral bacteria.

Changes in their saliva can place a person at greater risk for cavities.

Any alteration in the quantity or quality of a persons saliva will reduce those benefits that it provides. Having xerostomia, which refers to a state of diminished salivary flow, can tip the balance between tooth demineralization and remineralization in favor of the latter, and therefore tooth decay formation.

Xerostomia - What causes it?

You may have noticed that, when you first wake up, your mouth seems dry and stale. This is because when we sleep our body curtails the amount of saliva that our salivary glands produce.

Beyond this nocturnal mouth dryness, some people will notice that their mouth is chronically dry. This may be related to the person's age. With increasing age our salivary glands tend to work less effectively. And as a result the composition and quantity of our saliva changes. Either one of these factors can lessen the preventive benefits of saliva and put us at greater risk for cavities.

Xerostomia can also be a side effect of the medication a person is taking. Antihistamines (allergy and cold medications), antidepressants, blood pressure agents, diuretics, narcotics, and anti-anxiety medications are each known to cause mouth dryness.