mouth and dental disorders
Cavities
Symptoms of Cavities
Whether tooth decay causes pain depends on which part of the tooth is affected and how deeply the decay extends. A cavity in the enamel causes no pain. The pain starts when the decay reaches the dentin. At first, people may feel pain only when hot, cold, or sweet foods or beverages come in contact with the affected tooth. This type of pain often indicates that the inflammation in the pulp is reversible. If the cavity is treated at this stage, dentists can restore the tooth, and most likely no further pain or chewing difficulties will develop. A cavity that gets close to or actually reaches the pulp causes irreversible damage. Pain lingers even after a stimulus (such as cold water) is removed. The tooth may hurt even without stimulation (spontaneous toothache). If irreversible damage to the pulp occurs and the pulp subsequently dies, the pain may stop temporarily. The tooth then may become sensitive when people bite or when the tongue or a finger presses on it because the area at the end of the root has become inflamed or because infection has developed at the root. Infection may produce a collection of pus ( Periapical Abscess ), which causes constant pain that is worse when people bite. 