What is tooth decay?

Tooth decay refers to the loss of minerals from tooth structure caused by bacteria.
Photograph of the lower right deciduous teeth, one of which has developed an apparent cavity.Animation of the longitudinal section of a tooth crown with decay started in enamel and then all the way to dentine leading to apparent cavity.

Why does a tooth become decayed?

The tooth surfaces are normally covered with dental plaque. The bacteria in the dental plaque will metabolize the sugars in your food and produce acids which will demineralize the tooth surface.
Animation of the longitudinal section of a tooth crown with the acids produced by bacteria, resulting in enamel discoloration indicating mineral loss from the enamel.

Saliva can reduce acid attacks towards teeth by neutralizing it and prevent further loss of minerals. However, it must have enough time for saliva to work.
Animation of the longitudinal section of a tooth crown. It is protected by saliva, resulting in the colour of enamel turning white indicating the halting of mineral loss and the replenishment of minerals.

If we eat and drink frequently, saliva will not have enough time to work. The minerals on tooth surface will continue to lose out, and then tooth decay may occur.
Animation of the longitudinal section of a tooth crown with bacteria pouring acids repeatedly in a short period of time resulting in the continuous discolouration of enamel, indicating that the mineral loss is continuous and the tooth decay spread to dentine.

Symptoms and treatment methods of tooth decay

Early stage of tooth decay

Decay usually occurs at enamel of the tooth. Early stage of tooth decay is usually painless and the tooth seems undamaged from naked eye. Therefore, it is difficult to notice the decay.
Photograph of the longitudinal section of a tooth crown showing initial decay.

Treatment:

The early tooth decay can be restored by application of concentrated fluoride by dentist.
Animation showing the longitudinal section of a tooth at its initial stage of tooth decay.  An appropriate amount of fluoride has been applied to the decay resulting in the remineralization of the decayed portion.

Tooth decay spreads into dentine

When tooth decay spreads into dentine, a cavity may appear, and pain is felt when eating
Animation of the longitudinal section of a tooth crown with decay started in enamel and then all the way to dentine leading to apparent cavity.

Treatment:

Tooth decay spreads into the pulp

At this stage, the carious cavity is obvious and cause severe pain. The pulp tissues are infected by the bacteria and may become inflamed or even necrotic. The bacteria may spread from the pulp to the tooth surrounding tissues via the apex of the tooth, leading to the formation of abscess.
Animation of the longitudinal section of a tooth crown showing that the caries starts from enamel and then all the way to the dentine leading to pulp infection and inflammation.

Treatment:

Consequence of tooth decay

Methods to prevent tooth decay

Keep a good dietary habit

Every time when we eat, demineralization occurs at the surface of our teeth and creates a chance for getting tooth decay. The more often we eat, the more chances we have to get tooth decay. Therefore, having regular meals three times a day with sufficient amount of food during each meal will reduce the frequency of meals. In addition, drink plain water to quench thirst. This can reduce the chance of getting tooth decay. If you feel hungry in between meals, you may snack once.
Photograph showing that you may snack once between meals.

Brush your teeth with fluoride toothpaste

Fluoride strengthens the teeth by increasing their resistance to acid attack. Fluoride also facilitates minerals to re-enter the teeth (remineralization) and helps restore early tooth decay.Therefore, you should brush in the morning and before bed at night with fluoride toothpaste.
Photograph of a child brushing his teeth in the morning and before bed at night.

Regular dental check-up

Have regular dental check-up at least once a year so that tooth decay. can be diagnosed at an early stage. Preventive dental treatments such as fissure sealants can be applied.

Last revision date: 18 January 2012