Have you ever experienced that sensation of sudden painless and sharp toothache following eating an ice cream or chilled beverage? A quarter of people suffer from sensitive teeth. They are protected from the outside by enamel as well as the dentin layer inside that contains nerve endings. So, if there’s an enamel crack and there is something incredibly hot, cold, sweet, or sour, it can result in a certain amount of tooth sensitivity. It may last between just a few seconds to hours.