Caries is a type of infection that occurs in the teeth due to the activity of certain microorganisms that live in the oral cavity. One of the bacteria most commonly associated with tooth decay is Streptococcus mutans, although there are many other bacteria that can cause it.
Bacteria are found naturally in the mouth, which increases their reproduction and activity when they have an appropriate growth medium. The presence of leftovers, especially sugary foods, increases the metabolism of bacteria associated with the appearance of dental caries.
The food that these bacteria metabolize leads to the release of acids, which gradually erode and end up destroying tooth enamel. If there is no proper balance between mineralization and enamel destruction, caries appears in the affected area.