The process of scaling is asking medical history, oral examination, preoperative information, intraoral disinfection, ultrasonic cleaning, postoperative examination, rinsing and polishing, and medical advice. 1. Ask for medical history, ask the patient about past history, allergy history, infectious disease history and systemic disease. Ask whether the patient is equipped with a pacemaker or other devices. Ultrasonic cleaning is contraindicated in patients with pacemakers. 2. Oral examination, check the hygiene of the patient’s mouth, gums, teeth and preoperative medical records. Preoperative intraoral high-definition photographs can also be taken to document the intraoral situation. 3. Preoperative notification, tell patients with severe periodontitis that intraoperative bleeding is a normal phenomenon, do not be nervous, and that postoperative cold and heat discomfort needs to be adapted. 4. Oral sterilization, 1% chlorhexidine solution for 30~60 seconds. Ultrasonic cleaning, choose ultrasonic scaler to remove calculus and soft scale on the surface of teeth. The working power should not be too large, avoid staying in the same position for too long, give water spray cooling, check at any time. 5. Post-operative inspection, post-scaling inspection, visual inspection of the tooth surface with or without missing, probing inspection of the teeth near, far in the neighboring surfaces and gingiva with or without uncleaned large pieces of calculus. 6. Rinse and polish, after checking no problem, choose 0.12%~0.2% chlorhexidine solution or 3% hydrogen peroxide solution to rinse the periodontal pockets. Low-speed bender polishing brush for tooth surface polishing. Patients with periodontitis should be coated with iodized glycerin in the gingival sulcus, which has an anti-inflammatory effect. 7. Medical advice, insist on brushing at least twice a day for not less than three minutes each time. It is recommended that healthy people do teeth cleaning every six months to half a year. Soreness from cold and heat after scaling will be reduced day by day within a week.