scaling is cleaning of teeth which done in a dental clinic or dental office with special instruments .
those are peizo electric ultrasonic scalers.
Ultrasonic scalers are used to remove calculus rapidly from the tooth surface. The scaling tip vibrates in the ultrasonic range of 20-45 kHz (i.e. 20,000 to 45,000 times per second), with an optimum frequency between 18 kHz and 32kHz.