Dental Caries

Dental caries, the most common disorder affecting the teeth, is an infectious transmissible disease where acids produced by bacteria dissolve the teeth.

Certain bacteria such as Streptococci mutans and Lactobacilli, can be transmitted for example from parents to children. These bacteria are cariogenic, which means decay-causing. They initiate a sticky film, known as dental plaque, on the surface of the tooth. Bacteria in dental plaque use fermentable carbohydrates to form acids. Fermentable carbohydrates are sugars and other carbohydrates from food and drink that can be fermented by bacteria. The acids formed dissolve minerals such as calcium and phosphate from the tooth. This is called demineralisation.

But tooth decay is not inevitable. Saliva clears food debris from the mouth, neutralises acids produced from plaque bacteria and provides calcium and phosphate to the teeth in a process called remineralisation. Saliva also acts as a reservoir for fluorides from toothpaste or from fluoridated water. Fluoride helps control dental caries by remineralising the teeth and inhibiting bacterial acid production, which reduces or slows the decay process.

Tooth decay only occurs when the process of demineralisation exceeds remineralisation over a period of time.