We have lot of bacterias in our mouth which is a normal thing. While some of the bacteria can be harmful, most are not and some are even helpful.
Certain types of bacteria, however, can attach themselves to hard surfaces like the enamel that covers teeth. If they’re not removed, they multiply and grow in number until a colony forms. More bacteria of different types attach to the colony already growing on the tooth enamel. Proteins that are present in saliva (spit) also mix in and the bacteria colony becomes a whitish film on the tooth.This film is called plaque, and it’s what causes cavities.
The plaque that forms on teeth and doesn’t get washed away by saliva or brushed away by toothbrush produces acid as it eats up sugar. This acid is produced inside the plaque and can’t be easily washed away by saliva. The acid dissolves the minerals that make tooth enamel hard. The surface of the enamel becomes porous – tiny holes appear. After a while, the acid causes the tiny holes in the enamel to get bigger until one large hole appears. This is a cavity.
