Tooth decay on teeth is collectively known as dental caries, and dental caries is classified as demineralized, shallow, medium, deep and deep caries near the pulp. For demineralized caries, no treatment is done and the patient is only explained to control the oral hygiene. The treatment of superficial caries is to grind out the caries and fill the treatment. For medium caries, the treatment is capping and then filling. The treatment for deep caries is capping, bedding and filling. The treatment for deep caries near pulp is pacification, then after one month, observe the pulp condition, if the pulp condition is good, remove the pacifier, cover the pulp, bedding and filling treatment. If the pulp symptoms still exist, root canal treatment is needed.