Dental caries is an infectious disease of the teeth that results in destruction of organic matter of the tooth and the calcified tissues such as, the enamel, dentin and the cementum in the mouth. Dental caries is also known as tooth decay or a cavity.
Tooth decay/ dental caries is caused by bacteria which produce acid in the presence of carbohydrates that are fermentable for example, glucose, sucrose and fructose. Such foods include breads, cereals, soda, fruits, cakes or candy. The bacteria living in the mouth digests these foods and turns them into acid. This acid combines with the food particles in the mouth and saliva to form plaque. These acids in plaque are what dissolves the enamel and create holes in the teeth. These holes are referred to as cavities or caries.
An increase in the mineral content of the tooth destroys the tooth as it is sensitive to increased acidity. Acidic foods lead to the decay of the teeth. The most common indication that one has tooth decay is the appearance of a white chalky spot on the tooth. This indicates that the enamel, which is the outer layer of the tooth, is dissolving. As decay continues, the chalky spot turns brown. Demineralization causes the area to be soft. Continued decay to the layers where the nerves are located causes pan and sensitivity to the teeth.
Dental caries can occur on any surface of a tooth that is exposed to the oral cavity but not the structures that are retained in the bone. Caries occur from demineralization of acids that exceeds saliva and fluoride demineralization. Although most food that is trapped by the teeth is left between the teeth, 90% of the cavities in teeth appear in the pits and fissures on the chewing surfaces where saliva, fluoride and even brushing cannot reach.
Tooth decay does not occur suddenly, it occurs due to continuous lack of proper oral hygiene. Lack of flossing and brushing the teeth regularly leads to plaque buildup which initiates dental caries. The organisms that are responsible for the initiation of tooth decay are streptococcus mutas and lactobacillus. These organisms do this by releasing acids which lead to the decay. Caries cannot occur where there is no susceptible host, a suitable substrate, a cariogenic (acidic) environment and the frequency of the exposure of the acid.