A dental scaler comprises a hollow sleeve and, arranged inside it, a vibrating piezoelectric transducer bearing a scraper, the extremity of which protrudes from the sleeve, and includes an amplifier connected to the transducerk. The transducer includes a base, of a series of piezoelectric chips on the...http://www.google.co.uk/patents/US5059122?utm_source=gb-gplus-sharePatent US5059122 - Dental scaler
