The pain when the incisor is knocked often indicates the inflammation of the root tip of the incisor, the most common source of the inflammation of the root tip of the incisor is the incisor tooth decay, caries, which causes the pulp lesion and further develops into the root tip inflammation. When the incisor has knocking pain, first of all, we should check whether there is tooth decay, whether there is tooth decay, for the examination of incisor tooth decay should check the tooth decay on the adjacent side of the incisor, sometimes when there is tooth decay on the adjacent side of the incisor, it will show as a color change at the gap of the incisor, there will be a black color change, at the same time, apical inflammation often suggests that the pulp has necrosis, so the crown will have color change, also need to check carefully, in addition, incisor tooth Apical inflammation may originate from trauma to the incisor, causing further infection of the pulp. This is the time to carefully inquire about the history of trauma to the incisor, and if necessary, to take a film for further examination. For more serious knocking pain, the tooth should be drilled and opened for drainage, followed by further root canal treatment, but of course, incisor buckling pain may also be caused by periodontal disease, and periodontal disease causing incisor knocking pain should be accompanied by a certain degree of loosening, so it is also necessary to take a film for further examination of periodontal inflammation.