Three-year-old baby toothache, oral examination, take whole mouth surface tomography film after treatment, as follows: 1, the formation of deep caries cavity of milk teeth: cold, hot, acid, sweet and pain, you can use a sharp digging spoon to remove large pieces of decay, low-speed ball drill to grind away the discoloration of the tooth body tissue, the use of clove oil zinc oxide to temporarily close the cavity, pain relief after the double-layer matting, repair defects. 2, the formation of caries in the neighboring surface of the milk tooth When food residues are retained and cause gingival swelling and pain, food fibers can be removed, adjacent cavities can be prepared, and glass ionomer cementum can be used to repair the cavity, paying attention to the removal of excess material and preventing the formation of overhanging protrusions.3. X-rays show that pulpitis and apical periapical periodontitis have occurred in the milk teeth: the pulp cavity can be grinded under local anesthesia, the infected pulp can be removed, and iodine-formaldehyde paste can be applied to fill the root canals, and the metal and resin preformed crowns can be fabricated for repairing the defects.