Teeth that hurt when you touch them may have several possibilities: 1. Invisible cracks in the teeth, when chewing hard foods while eating, which are especially prone to cracks in the teeth. When the crack is deeper, it is especially prone to mechanical pain, and it is possible that the tooth will feel painful at a certain moment of biting. This situation is generally recommended not to chew too hard food in the near future, and it is recommended to adjust, you can properly apply fluoride to promote its mineralization. 2, the teeth hurt when you touch them, it may be due to the teeth have been cracked. And this time the tooth splitting, if it is the crown root fracture need to extract the tooth; if it is the apical 1/3 fracture, this situation can be done to fix the tooth and regular observation. 3, the tooth touches on the pain, it is recommended to check the root tip of the tooth whether there is inflammation, if the tip of the root abscess, the tooth will also be pain, this situation needs to do root canal treatment, take out the tooth nerve; and appropriate oral anti-inflammatory drugs, when the root canal treatment also need to do ceramic teeth. After the root canal treatment, the tooth also needs to be restored with porcelain braces.