A Answers (3)
We get cavities in teeth from a substance in the mouth called plaque, which sticks to teeth and contains acid-producing bacteria that can cause tooth decay and a cavity or hole in the tooth. When we eat sugary or starchy foods, acids are produced that attack and break down the enamel or protective surface of our teeth, which, over time, can also lead to decay of the inner part of a tooth.
American Dental Association answeredYour teeth are covered with plaque, a sticky film of bacteria. After you have a meal, snack or beverage that contains sugars or starches, the bacteria release acids derived from dietary sugars that attack tooth enamel. Repeated attacks can cause the enamel to break down and may eventually result in cavities.
Caries is the disease process that leads to cavities or the "holes" in the mouth that we are all too familiar with. This is an infectious process that is caused by a few different families of bacteria that infect the mouth very early in life, generally thought to be aby age 2. Once the mouth of a child is infected with these caries causing bacteria, everytime he or she is exposed to sugary substance or anything that contains carbohydrates for that matter, the caries causing bacteria begin to produce and deposit acid onto the tooth surfaces. When this continue over days, weeks and months on areas that are not regularly cleansed with a tooth brush and properly exposed to fluoride (2 minute of foamed tooth paste is best during brushing), the hard enamel of the teeth breaks down resuting in dental "cavity" or a "soft hole" in the tooth. As the bacteria contiue to grow and produce more acid, more and more of the tooth structures and minerals are lost until this process get close to the dental pulp or the nerve of the tooth. The nerve of the tooth usually will respond by pain signals as it is now exposed to hot, cold, pressure or sweets that can not reach it easily and stimulate it.