Scaling that is periodontal scaling, periodontal abscess and wisdom teeth in the acute stage of peri-coronitis patients are not recommended for periodontal scaling, patients with old pacemakers, and hepatitis, tuberculosis, AIDS and other infectious diseases are not recommended for ultrasonic scaling. 1. Patients with periodontal abscess and acute stage of wisdom tooth pericoronitis: periodontal scaling may lead to the spread of infection or cause secondary infection, periodontal abscess can wait for pus drainage, inflammation relief and then periodontal scaling, wisdom tooth pericoronitis can wait for wisdom tooth extraction, inflammation elimination and then periodontal scaling. 2. Patients with old pacemakers: ultrasonic cleaning can produce electromagnetic radiation interference, causing dizziness and arrhythmia, and it is recommended to use hand instruments for cleaning. 3. Patients with infectious diseases: such as hepatitis, tuberculosis, AIDS, etc., blood and pathogenic bacteria can pollute the environment of the clinic with the spray, so it is recommended to use hand instruments to clean the treatment. It is recommended to go to regular medical institutions to receive professional treatment.