Oral health is dependent on the “cleaning” of your teeth. Dental cleaning is a good way to clean your teeth. However, some people are addicted to dental cleaning and want to go every three or four months, thinking that “the more diligently you clean your teeth, the healthier they are”. Some people, however, feel that their teeth are prone to soreness for a long time after each cleaning, “will it hurt the teeth?” How many times a year is the right number of teeth cleaning? In fact, there are two kinds of dental cleaning: therapeutic and preventive. Preventive scaling can be done once a year, but if it is too frequent, the teeth will be easily damaged. Therapeutic scaling is different. It is mainly for people who have dental calculus, long-term tobacco plaque and tea tartar. Generally, after the first treatment, you need to maintain the frequency of once every three months to six months, and after the situation improves, you can insist on once a year for two or three years. For people with uneven teeth, prone to food debris clogging or born with imbalance of phosphorus and calcium metabolism resulting in imbalance of the ratio of these two elements in saliva, they should insist on scaling once a year after therapeutic scaling. Since calculus is equivalent to putting a layer of “armor” on the teeth, making them “sluggish”, once the stone is removed, the teeth will naturally have a period of discomfort, afraid of acid and cold, but this normal “sensitivity But this normal “sensitivity” can usually be relieved in a month, and later when the teeth are cleaned again can also adapt to the changes. It should be reminded that scaling using ultrasonic shock tartar can cause slight damage to the tooth surface, and polishing must be done after scaling to compensate. During the sensitive period after scaling, you should not eat irritating foods such as “sour, spicy, hot” and carbonated beverages such as cola should be consumed sparingly to avoid erosion of sensitive teeth. Pure milk, fruit juices, etc. are not harmful. In addition, the habit of smoking, drinking strong tea and coffee every day will accelerate the speed of pigmentation on the teeth, which will make the scaling of the teeth to be wasted, so it should be quit.