Home Dentistry Articles Dental cavities
Tooth decay, or dental caries, is a disease
of the teeth resulting in damage to tooth structure. The cavities
formed because of dental caries are called dental cavities.
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
Bacteria (such as peptostreptococci) are normally
present in the mouth. The bacteria convert 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 than
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.
toothache -- particularly after sweet or hot
or cold foods or drinks
visible pits or holes in the teeth .
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, such as a dental
explorer. 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.
A Picture showing various stages of dental
caries is shown here.
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
In filling teeth, the decayed material is removed
(by drilling) and replaced with dental fillings, made of 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 these materials 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.
Removal of the decayed tooth extraction is
performed if the tooth is too far destroyed from the decay process
to effectively restore, or if the tooth considered non-functional
(lack of opposing tooth, or tooth is in a non-useful position)
or the patient does not wish to undergo the expense or procedure
of restoring the tooth.
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.
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 possible 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.
It has also been found that certain kinds of
cheese like cheddar can help counter tooth decay if eaten soon
after having eaten foods potentially harmful for teeth.