If the caries is not treated for a long time, the cavity will be bigger and bigger, when the cavity is close to the pulp, it will be very painful when the patient encounters cold, hot, sour and sweet, then it needs to be filled early. For deep caries, if there is softened dentin at the bottom of the cavity, it is necessary to determine whether to fill the cavity according to the depth of the cavity, the length of pain, the nature of softened dentin below, the residual amount and the performance. Usually, the decayed tissue can be removed by high speed handpiece, and the restorative soft dentin can be retained, then calcium hydroxide can be used as a base, and after 3 months of temporary filling, it can be determined whether the restorative dentin is formed or not, then the soft dentin at the bottom of the cavity can be removed again, and permanent filling can be performed. In conclusion, when the tooth is deeply decayed, do not rush to let the doctor perform a one-time filling restoration, but wait patiently for the restorative dentin to form. If the pulp is exposed and you are not sure about the pulp, you can use calcium hydroxide cushion and zinc oxide clove oil mucilage powder to temporarily fill and soothe the treatment, and when there is no painful adverse reaction after observing 1-2 weeks, remove the upper layer of zinc oxide clove oil mucilage powder and fill and cushion again, and observe the final filling after 3 months.