The main purpose of scaling is to prevent periodontal diseases, and the effect of scaling is limited for caries prevention. The main purpose of general scaling is to remove the plaque and tartar from the periodontium, to make the gums healthy, so that the gums are no longer in the inflammation state and the gums no longer bleed. It has relatively small effect on tooth decay, but it also has some effect on preventing tooth decay. Because during the scaling process the doctor can see every surface of the tooth and at the same time can understand the presence of early caries. If the tooth is found to have the tendency of caries, the scaling doctor will suggest the patient to fill and treat the early caries as soon as possible. Therefore, although the main purpose of scaling is not to prevent cavities, it can effectively make the early detection of cavities and early treatment.