The causes of tooth pain often include cavity, poor oral hygiene, embedded food, hidden tooth fracture, wrong brushing method, etc., as follows: 1. Bacteria can cause pulp infection and severe pain. 2.Poor oral hygiene: If you don’t pay attention to oral hygiene, the food residue in the mouth can combine with saliva to form calculus and stimulate gum swelling and pain. 3.Embedded food: When food fiber is often embedded between two teeth, it will cause gum papillae redness, swelling and pain. 4.Hidden tooth fissure: When hidden fissure occurs on the tooth surface, the stimulation outside can be transmitted to the pulp along the fissure and cause pain. 5.Hidden tooth fissure: When the tooth surface is hidden, the stimulation outside can be transmitted to the pulp along the fissure and cause pain. 5. Wrong way of brushing: When brushing horizontally for a long time, wedge-shaped defects are produced in the neck of the teeth, and pain occurs when cold or hot stimuli are encountered.