Tooth decay, also known as dental caries, is a disease in which bacteria invade the hard tissues of the teeth, causing them to decay and disintegrate. For tooth decay, it is necessary to go to a professional dental institution for treatment. Early tooth decay, that is, in the state of shallow caries or medium caries, can be cured after one treatment in the dental institution by applying a high-speed turbine drill to remove the decayed and decayed portion of the tooth and prepare the corresponding hole shape, and then fill it up with a special filling material. However, once the tooth decay develops to a deeper part and causes pain in the affected tooth, it means that the tooth decay has produced pulpitis, and the treatment at this time is to open up the pulp for systematic root canal treatment, and to protect the decayed tooth by applying a crown restoration.