Dental Caries

What are dental caries?
Tooth decay, known technically as dental caries, is one of the most common health complaints in the world.

It is a disease of the teeth that affects individuals of all ages, although it is particularly common in children and young adults.

Dental caries affect individuals of all ages, although it is particularly common in children and young adults. Photo Credit: Nobel Biocare

Its incidence has been fueled by an increase in sugars in the diet, and poor dental hygiene. Dental caries occurs when the tooth enamel is destroyed.

Decay begins at the tooth's hard external surface, and may advance to internal structures of the tooth including the dentin and pulp. The earlier decay is treated, the better chance of saving the tooth.

What causes tooth decay?
The bacteria that are normally present in the mouth change the food (primarily sugars and starches) we eat into acids. Over a period of time, the bacteria and acids form a sticky deposit called dental plaque that clings to the teeth.

Tooth decay is caused by dental plaque that collect, in particular, around the gum line, the edges of fillings and the grooved surfaces of the teeth. Plaque is made up of food debris, saliva and the bacteria that are normally present in the mouth. If plaque is allowed to collect over time it will harden into a substance called tartar. Both tartar and plaque contain acids which, over time, can dissolve away the protective, hard enamel coating of the tooth, resulting in holes or cavities.

Most cavities slowly form over a period of months, or even years and are usually painless, but they can grow very large, and damage the much softer internal structures of the tooth such as the dentin and the pulp, which is found at the core.

If left untreated, cavities can lead to a serious complication such as the development of a tooth abscess - the build up of pus resulting from a bacterial infection of the centre of the tooth. Infection may spread out from the root of the tooth and to the bones supporting the tooth. Tooth infection can kill the nerve and blood vessels of the tooth, and ultimately the tooth itself.

Plaque and tartar also irritate the gums, and lead to a gum disease called gingivitis. Children's teeth primarily decay in the grooves. In addition to the grooves, older adults decay in other areas, including the roots of the teeth, which may be exposed as a result of receding gums.

What are the symptoms?
The most obvious sign of tooth decay is toothache, particularly after hot or cold foods or drinks. However, pain may not be present until decay has reached an advanced stage.

Pits or holes may also be visible in the teeth.

Most tooth decay is discovered at an early stage during a routine check up.

Is diet a factor?
Yes, sugar and starches (such as candy, cakes, cookies, milk and fizzy soft drinks) are responsible for much of tooth decay, but sour or acidic foods (such as lemons and fruit juices), also contribute to decay because they change the pH (acidity level) in the mouth. Eating a diet rich in sugar and starch therefore increases the risk of tooth decay, and sticky foods can be a particular problem because they are more likely to remain on the surface of the teeth.

Frequent snacking also increases the amount of time that acids are in contact with the teeth.

In the absence of good oral hygiene, it doesn't take long for damage to begin. The acids generated by the breakdown of food stuff in the mouth can begin to attack the tooth enamel within 20 minutes of a meal.

How do you prevent tooth decay?
The best way to keep your teeth in healthy condition is to ensure that you clean them regularly to get rid of any plaque build up. Eating nutritious foods and visiting the dentist on a regular basis will also help prevent cavities.

Dentists provide these guidelines for preventing tooth decay:

• Brushing your teeth at least twice a day. Using a toothpaste containing fluoride is recommended as this provides the teeth with added protection from the effects of acid.
• Cleaning between the teeth daily with floss
• Rinsing out your mouth after eating sticky foods
• Eating well-balanced meals and limiting snacking
• Visiting the dentist on a regular basis for check-ups and cleanings
• If brushing is not possible, the next best thing is to rinse the mouth with water to neutralize the acids and change the pH level in the mouth, which may curb tooth decay.

How often should you visit your dentist?
It is also important to have a regular check up at the dentist - most dentists suggest once every six months to a year for a cleaning and a thorough examination. You should never hesitate to consult a dentist if you experience any problems or need emergency care.

How is tooth decay treated?
Unfortunately, even good oral hygiene does not prevent decay as the bacteria congregate in areas inaccessible to brushes and floss. Therefore regular visits to the dentist are important so that your dentist can remove the inaccessible plaque and tartar using a technique known as scaling.

Once the structure of a tooth has been damaged by decay, there is no way to repair it. However, if decay is picked up at an early stage its progression can be blocked. Decayed material can be removed, and replaced with a restorative material known as a filling.

If the decay is more extensive, then another option is a crown. The decayed or weakened area is removed and repaired and a covering jacket - the crown - is fitted over the remainder of the tooth.

If the nerve in a tooth has died, either from decay or a blow, then a dentist will consider root canal work. This involves removing the centre of the tooth, including the nerve and blood vessel tissue. The root is then filled with a sealing material, and the process is completed with a filling or, possibly, a crown.