| What Is It?
Dental caries is the medical term for tooth decay or cavities. It is caused
by acid erosion of tooth enamel. Many different types of bacteria normally
live in the human mouth. They accumulate (along with saliva, food particles
and other natural substances) on the surface of the teeth in a sticky film
called plaque. Plaque forms especially easily in cracks, pits or fissures in
the back teeth; between teeth; around dental fillings or bridgework; and near
the gum line. Some of the plaque bacteria convert sugar and carbohydrates (starches)
in the foods we eat into acids. These acids dissolve minerals in the surface
of the tooth, forming microscopic pits or erosions that get larger over time.
The damage can occur anywhere the tooth is exposed to plaque and acid,
including the hard outer enamel on the tooth crown or the unprotected
root of the tooth that has been exposed by gum recession. Caries
can penetrate the protective enamel down to the softer, vulnerable
dentin (main body of the tooth) and continue through to the soft tooth
pulp and the sensitive nerve fibers within it. No one really knows what
causes the pain associated with cavities, but theories include inflammation
caused by bacteria, exposure of the root surface and an imbalance of
fluid levels in the tubules inside the dentin.
Symptoms
Early caries may not have any symptoms. Later, when the decay has eaten
through the enamel, the teeth may be sensitive to sweet foods or to hot
and cold temperatures.
Diagnosis
A dentist will look for caries at each office
visit,
regardless of whether it is a routine visit or an appointment made by
the patient because of pain. The dentist will examine the teeth visually
and will probe the teeth with an instrument called an explorer to determine
if there are pits or areas of damage. Periodically, or if the dentist
suspects hidden caries, X-rays will
be taken by looking at the teeth.
Expected Duration
How long caries lasts is determined by the stage at which it is found.
White spots, indicating early caries that has not yet eroded through
the enamel, may be reversed if acid damage is stopped and the tooth is
given a chance to repair the damage naturally. Caries that has destroyed
enamel cannot be reversed. Most caries will continue to worsen and deepen
and with time, the tooth may decay down to the root. The amount of time
the erosion takes will vary from person to person. Caries can erode to
a painful level within months or it can take years to reach that stage.
Prevention
Cavities can be prevented by reducing the amount of plaque and bacteria
in the mouth. The best way to do this is by daily brushing
and flossing and professional dental cleanings twice a year. You also
can reduce the amount of acid in your mouth by eating sugary or starchy
foods less frequently during the day. Your mouth will remain acidic for
several hours after eating, so snacking throughout the day is more likely
to lead to caries than avoiding between-meal snacks. Chewing gum that contains
xylitol helps to counteract the acidity that occurs after eating.
Teeth can be strengthened by fluoride.
A dentist can evaluate your risk of caries and then suggest appropriate
fluoride treatments. In children, new molars can be protected by having
the dentist apply a sealant as soon as the teeth come fully into the
mouth.
Treatment
The standard treatment for caries is to fill the tooth.
After the dentist removes the decayed material in the cavity (usually
following the use of anesthesia to block the pain), the cavity is filled. Fillings usually
are made of a dental amalgam, which is a silver-gray material made from
silver alloyed with copper or other metals in order to improve durability,
or of a composite resin, which is tooth-colored for a better appearance.
Amalgams are used primarily in molars and premolars. Resins are used primarily
in the front teeth, although it is possible to use them in all teeth. Gold
inlay may be used if greater strength is needed, but this is more expensive.
If a cavity is large with extensive erosion, the remaining tooth may
not be able to support the amount of filling material that would be needed
to repair it. In this case, the dentist will remove the decay, fill the
cavity, and cover the tooth with an artificial crown.
Sometimes the crown of the tooth remains relatively intact, and there
is more damage in the interior of the tooth. In these cases, the dentist
may refer you to a dental specialist called an an endodontist for root
canal treatment.
In this procedure, the endodontist removes the tooth's pulp and replaces
it with an inert material. In most cases, the tooth's natural crown will
need to be replaced with an artificial crown.
When To Call A Professional
The early stages of decay are usually painless. Only regular professional
examinations and X-rays can detect early trouble. If you develop sensitivity
to chewing or to hot, cold or sweet foods or beverages, contact your
dentist.
Prognosis
If a cavity goes undiagnosed, it likely will cause the tooth to erode
significantly. Eventually, the tooth may be destroyed by uncontrolled
decay.
Having caries increases your risk of more caries for several reasons:
- The same oral care and dietary habits that contributed to the plaque
and acids that caused the initial cavity may cause more decay
- Bacteria tend to adhere to fillings and other restorations more than
to smooth teeth, so those areas will be more susceptible to new caries
- Cracks or gaps in the fillings may allow bacteria and food to enter
the tooth, leading to decay from beneath the filling
Additional Info
American Dental Association
211 East Chicago Ave.
Chicago, IL 60611
Phone: (312) 440-2500
Fax: (312) 440-2800
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