If the area of the cavity is not large, the treatment is relatively simple, only a high-speed turbine drill is needed to thoroughly remove the infected hard tissues of the tooth, and then fill the tooth with the filling material, usually composite resin, and the clinical time is about 0.5 hours to complete. If the cavity is already very bad and there is a transient pain, local anesthetic injection and indirect pulp capping are needed during the treatment process, and the clinical treatment time is relatively longer, taking about 1 hour to complete. If the infection of tooth decay has developed to pulpitis, the tooth should be treated with root canal, which contains many complicated steps and requires 2-3 times of clinical follow-up, each time with an interval of 1 week, and each clinical operation takes about 1 hour.