Tooth hypersensitivity, professionally known as dentin sensitivity, is a condition in which the teeth become sore in response to hot and cold stimuli, and in general the hard tissue of the teeth consists of the enamel on the outside and the dentin on the inside. The enamel is the hardest material and does not contain nerves, which protect the tooth from pain. If the enamel is chipped or severely abraded, the dentin is exposed and can become painful due to the presence of nerves in the dentin. The specific situation is that the dentin exposed in the mouth, when eating hot, cold or acidic food will appear obvious tooth soreness, pain, while going to the professional dentistry, dentists apply a probe to slide on the tooth surface, the teeth will also feel the obvious sensitive situation, usually you can use anti-allergic toothpaste, if the allergy is serious need to go to the professional dentistry treatment.