Cavities, also known as dental caries, are essentially the same thing. Cavities are a disease caused by bacterial infection of the hard tissues of the teeth, resulting in black holes on the tooth surface. If the cavity is deep, reaching or approaching the dental nerve, external stimuli from hot, cold, sweet, or sour sources can cause tooth pain. The term "tooth decay," commonly referred to as "worm teeth" by the public, fundamentally describes the same condition as cavities, not caused by any sort of worm but by bacterial pathogens. Thus, there is no difference between cavities and tooth decay; both are infectious diseases of the hard tissues of the teeth.