Cavities are holes that damage the structure of teeth. X-rays can reveal if a person has any cavities and some diseases.

 

Caries is a term used to describe the process in which some bacteria produce cavitation of the teeth. The group of bacteria which Caries is in makes up part of the normal oral flora, has a complex relationship with the host where it uses sugar that the host consumes to metabolize as energy, and produces acid which subsequently dissolves the teeth.

 

Caries can refer to not one, but many species of bacteria including lactobacillus and viridians streptococci. These bacteria use ingested carbohydrates for metabolism and produce acid which subsequently dissolves the teeth. Pits and fissures and interproximal smooth surfaces are the most commonly colonized areas of the teeth.

 

Attempting to prevent dental caries involves reducing the factors that cause demineralization, and increasing the factors leading to re-mineralization. Unchecked demineralization leads to cavities which may penetrate the underlying dentine to the tooth's nerve-rich pulp and lead to toothache.

 

In moderation, fluoride is known to protect the teeth against cavities. It toughens the teeth by replacing the hydroxyapatite and carbonated hydroxyapatite minerals of which the enamel is made with fluorapatite, which is harder to dissolve by acid. It also reduces the production of acids by bacteria in the mouth by reducing their ability to metabolize sugars. The addition of fluoride (sodium monofluorophosphate) to toothpaste is now very common, and may explain the decline in dental caries in the Western world in the past 30 years.

 

Some believe that a diet rich in fluorine salts, particularly in childhood, can lead to stronger enamel which is less susceptible to decay. Fluoridation of drinking water remains a controversial issue. However, in many parts of the world, the natural water supply may be sufficiently rich in fluorides to supply the needs of children without additional sources being required.

 

Caries is an infectious disease and is treated only by prevention. Once the decay process begins, caries can be eliminated only through the removal of the bacteria. Fluoride can be used to re-mineralize decalcified enamel, but new tooth structure cannot be regrown.

 

When a patient gets a filling, the dentist mechanically removes the bacterial flora and dead tooth structure and replaces it with a restorative material (metal or glass). This was, traditionally, achieved using gold or a compound of metals called amalgam. Amalgam fillings have been the cause of some public concern because they contain mercury. Modern tooth-colored composite or ceramic are used in addition to traditional amalgam fillings.
 

As a last resort, teeth affected by caries may be extracted, preferably under local or general anesthetic. The extracted teeth may be either replaced with a denture or if extracted much before permanent teeth erupt, the space may be maintained by specialized orthodontic appliances called Space Maintainers.