What is Dental Caries?

Dental caries is an infectious disease that can lead to cavities (small holes) in the tooth structure that compromises both the structure and the health of the tooth.


Dental caries is the second most common disease in our community after the common cold. However, it can be prevented with proper oral hygiene. The rate of dental caries has declined due to fluoridated water and improved oral hygiene techniques.

The decline of caries is measured by the number of decayed, missing or filled teeth DMFT affect by caries. The DMFT rates of 5-6 years old, 12 years old, 21-24 years old, and 35-44 years old in 1999 were 1.66, 0.89, 3.7 and 13.5 respectively.

Risk Factors

There are several risk factors associated with dental caries. The 3 main factors that lead to dental caries are sugars, oral bacteria and the time these are combined in the presence of the tooth. These factors increase a persons susceptibility to developing caries and play varying roles in the development of caries, depending on its nature.

For example, sticky sugary foods are much more likely to cause dental caries than non sticky sugary foods. It is important to recognize that people with teeth defects are predisposesd to dental caries.


Dental caries is caused by bacteria producing acids from the consumption of sugars. The acid can cause local demineralisation of the tooth surface. If damage to the tooth is not significant, the protective qualities of saliva may stop further demineralisation of the tooth and remineralization will occur. Also, proper oral hygiene e.g. brushing teeth 3 times a day reduces the development and progression of caries.

If caries are allowed to continue to progress, much more of the tooth structure will be lost and there is an increased risk of loss of the entire tooth and infection such as a tooth abscess.


The patient usually complains of a painful tooth that is made worse when eating hot, cold or sugary drinks. There may be discolouration or holes present on affected tooth, which may cause annoying impaction of small food pieces. If the tooth has become infected, the patient’s face may appear swollen on the affected side.

Clinical Examination

The early sign of dental caries is a chalky white appearance of the enamel surface. If the caries progresses, the damaged enamel surface becomes dark brown or black. A late sign of dental caries is holes or cavites in the affected tooth. The affected tooth is probed to check the depth of the hole. If the tooth is painful when probed, the tooth is still alive. If not, the tooth is not vital any more.

How is it Diagnosed

An x-ray confirms diagnosis of dental caries.


The prognosis of dental caries depends on the health of the patient, oral health practices and the extent of dental caries. Early signs of dental caries may be reversed with minor dental intervention and improved oral hygiene. If dental caries has lead to holes in the tooth, the lost tooth structure must be filled and rebuilt with dental materials. If there is significant damage to the tooth and signs of infection, the tooth should be removed and the infection treated.


The main goal is to keep as much tooth structure as well as preventing further complications. Caries that are superficial may require only fluoride treatments to help with remineralisation.

If caries have lead to cavities, the caries must be removed and the repaired with dental materials such as composite and amalgam. If a significant amount of tooth structure is lost, the tooth may have a crown placed over it. If much of the tooth structure is lost and the tooth is vulnerable to infection, the tooth may need root canal treatment.

The final stage will be to remove the tooth if it is untreatable. The patient may then chose to have an implant (a fake tooth put into the jaw) or partial denture, depending on oral health and financial status.


  1. Australian Dental Association,viewed 28 March 2007, at http://www.ada.org.au/.
  2. Bowen, WH & Tabak, LA 1993, Cariology for the nineties, University of Rochester Press, NY.
  3. Fejerskov, O, & Kidd, EAM 2003, Dental caries: the disease and its clinical management, Blackwell, Oxford.
  4. Mitchell, DA 2005, OXFORD HANDBOOK of Clinical Dentistry, 4th edn, Oxford University press, New York.
  5. Silverstone, LM 1981, Dental caries: aetiology, pathology & prevention, 2nd edn, Macmillan, London.

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