Definition
A disease of the teeth resulting in
damage to tooth structure.
Alternative names
Dental cavities; Tooth decay;
Cavities - tooth
Causes, incidence, and risk factors
Dental caries
(tooth decay) is one of the most common of all disorders,
second only to the common
cold. It usually occurs in children and young adults but
can affect any person. It is the most important cause of tooth
loss in younger people.
Bacteria are normally present
in the mouth. The bacteria convert all foods-especially sugar
and starch-into acids. Bacteria, acid, food debris, and saliva
combine in the mouth to form a sticky substance called plaque
that adheres to the teeth. It is most prominent on the grooved
chewing surfaces of back molars, just above the gum line on
all teeth, and at the edges of fillings. Plaque that is not
removed from the teeth mineralizes into calculus (tartar).
Plaque and calculus irritate the gums, resulting in
gingivitis
and ultimately periodontitis.
The acids in plaque
dissolve the enamel surface of the tooth and create holes in
the tooth (cavities). Cavities are usually painless until they
grow very large inside the internal structures of the tooth
(the dentin and the pulp at the core) and can cause death of
the nerve and blood vessels in the tooth. If left untreated a
tooth
abscess can develop.
Plaque and bacteria begin to
accumulate within 20 minutes after eating, the time when most
bacterial activity occurs. If plaque and bacteria are left on
the teeth, cavities can develop and untreated tooth decay can
result in death of the internal structures of the tooth and
ultimately the loss of the tooth.
Dietary sugars
and starches
(carbohydrates)
increase the risk of tooth decay. The type of carbohydrate
and the timing and frequency of ingestion are more important
that the amount. Sticky foods are more harmful than nonsticky
foods because they remain on the surface of the teeth.
Frequent snacking increases the time that acids are in contact
with the surface of the tooth.
Prevention
Oral
hygiene is the primary prevention against dental caries.
This consists of personal care (proper brushing at least twice
a day and flossing at least daily) and professional care
(regular dental examination and cleaning, every 6 months).
Select X-rays may be taken yearly to detect possibily cavity
development in high risk areas of the mouth.
Chewy,
sticky foods (such as dried fruit or candy) are best if eaten
as part of a meal rather than as a snack. If possible, brush
the teeth or rinse the mouth with water after eating these
foods. Minimize snacking, which creates a constant supply of
acid in the mouth. Avoid constant sipping of sugary drinks or
frequent sucking on candy and mints.
The use of dental
sealants is a good means of cavity prevention. Sealants are
thin plastic-like coating applied to the chewing surfaces of
the molars. This coating prevents the accumulation of plaque
in the deep grooves on these vulnerable surfaces. Sealants are
usually applied on the teeth of children, shortly after the
molars erupt. Older people may also benefit from the use of
tooth sealants.
Fluoride is often recommended to
protect against dental caries. It has been demonstrated that
people who ingest fluoride in their drinking water or by
fluoride supplements have fewer dental caries. Fluoride
ingested when the teeth are developing is incorporated into
the structure of the enamel and protects it against the action
of acids.
Topical fluoride is also recommended to
protect the surface of the teeth. This may include a fluoride
toothpaste or mouthwash. Many dentists include application of
topical (applied to a localized area of the skin) fluoride
solutions as part of routine visits.
Symptoms
- toothache -- particularly after sweet or hot or cold
foods or drinks
- visible pits or holes in the teeth
Signs and tests
An examination of the teeth
reveals dental caries (cavities). Most dental caries are
discovered in the early stages during routine checkups. The
surface of the tooth may be soft when probed with a sharp
instrument. Pain may not be present until the advanced stages
of tooth decay. Dental
X-rays may show some cavities before they are visible to
the eye.
Treatment
Destroyed tooth structure does not
regenerate. However, the progression of dental caries can be
stopped by treatment. The goal of treatment is to preserve the
tooth and prevent complications. Ideally proper dental
education is the best weapon in preventing tooth
decay.
In filling teeth, the decayed material is
removed (by drilling) and replaced with a restorative material
such as silver alloy, gold, porcelain, or composite resin.
Porcelain and composite resin more closely match the natural
tooth appearance, and may be preferred for front teeth. Many
dentists consider silver amalgam (alloy) and gold as stronger
and are often used on back teeth, although there is a trend to
use high strength composite resin in the back teeth as
well.
Crowns are used if decay is extensive and there
is limited tooth structure which may cause weakened teeth.
Large fillings and weak teeth increase the risk of the tooth
breaking. The decayed or weakened area is removed and repaired
and a covering jacket or "cap" (crown) is fitted over the
remainder of the tooth. Crowns are often made of gold,
porcelain or porcelain fused to metal.
A root canal is
recommended if the nerve (pulp) in a tooth dies from decay or
from a traumatic blow. The center of the tooth, including the
nerve and vascular (blood vessel) tissue (pulp), is removed
along with decayed portions of the tooth. The roots are filled
with a sealing material. The tooth is filled and a crown may
be placed over the tooth if needed.
Prognosis
Treatment often preserves the tooth.
Early treatment is less painful and less expensive than
treatment of extensive decay. Anesthetics -- local, nitrous
oxide (laughing gas), or other prescription medications -- may
be required in some cases to relieve pain during or following
drilling or other treatment of decayed teeth. For those who
fear dental treatment, nitrous oxide anesthesia may be
preferred.
Complications
- tooth
abscess
- fractured tooth
- discomfort or pain
- tooth sensitivity
- inability to bite down on tooth
Calling your health care provider
Call your
dentist if a toothache
occurs.
Call your dentist for a routine cleaning and
examination if you have not had one in the last 6 months to 1
year. |
