title: The ultrasonic dental unit: a guide for the clinical application of ultrasonics in dentistry and in dental hygiene.
mesh_terms: D003777:Dental Prophylaxis / Q000266:history / Q000295:instrumentation*; D049672:History, 19th Century; D049673:History, 20th Century; D006801:Humans; D010510:Periodontal Diseases / Q000628:therapy; D014465:Ultrasonics / Q000266:history