Cavities form when carbohydrates, or sugars are left on teeth, as they provide food for the bacteria, already in your mouth, to grow. The bacteria produces an acid which causes cavities.
Mild tooth decay does not cause any pain, so small cavities are hard to notice, unless you, or your dentist examine your teeth for holes, and pits. The pain often associated with cavities usually only occurs when tooth decay is more advanced. Common myths about cavities are: kids get more cavities than adults, aspirin placed on a tooth will cure a toothache, if you have a cavity you will know it, all fillings ultimately need replacing, and cavities are the prime reason for root canals.
Truths about cavities are: sugars, and acids produce cavities, cavities are more likely between teeth, once tooth decay is treated, the decaying stops, and brushing and flossing daily, plus regular dental check ups are the best way to prevent cavities.