Ultrasonic scaling mainly removes tartar through vibration, cavitation and mechanical friction. 1. Vibration: ultrasonic scaler is mainly electrical energy into ultrasonic vibration, by adjusting the power to smash tartar. 2. Cavitation: ultrasonic scaler will spray water cooling, water droplets within the vacuum bubble will generate energy when collapsed, the plaque and plaque on the plaque to produce scouring effect, the plaque and blood stains away, clean the oral cavity. 3. Mechanical friction: ultrasonic tip is generally recommended and teeth parallel contact or <15 °, but its teeth and there is still contact, so there is mechanical friction. Good oral hygiene is the key to preventing caries and periodontal disease, it is recommended to clean the mouth regularly every 6~12 months.