Ultrasonics in dentistry

Abstract

PPROXIMATELY ONE HUNDRED YEARS ago, it was learned that certain crystal A elements contracted in a magnetic field. Shortly thereafter a similar property was discovered in certain metals which, if rod-shaped, contracted in the direction of their long axes. This invaluable information lay dormant until the beginning of the twentieth century when high frequency application of the magnetic field provided energy in the form of vibrations. Ultimately, vibrations were produced above the hearing range of humans to the ultrasonic frequencies. The addition of a waterborne abrasive to the vibrating device made it possible to remove hard substances. Transistors, quartz crystals, and jewels are cut in industry by this means. It is of particular interest to note that the first industrial use of the magnetostrictive cutting device was to prepare cavities in synthetic sapphires for the reception of gold inserts. It is no wonder then that the possibility of the use of ultrasonic energy presented itself to dentistry. The first use of this cutting method was reported in the Annals of Dentistry by Dr. Matthew C. Catuna in 1953.’ He prepared cavities in extracted teeth and reported the potential use of the ultrasonic device for this purpose. One year later, Dr. Carl Oman and Dr. Edmund Applebaum” reported in the New York State Dental Journal that an ultrasonic device had been successfully employed to prepare cavities in teeth of patients. Their report suggested several advantages of the ultrasonic method. Since its inception, dentistry has adapted industrial uses of energy to its need. The electric engine and modern rotary instruments are prime examples. The ultrasonic device provides another form of energy for dentistry. Dentistry, ever alert to improve its service, accepted the challenge and responsibility to determine the safety, effectiveness, and extent of usefulness of ultrasonics. Investigators throughout the nation in dental schools, hospitals, and the Armed Services undertook one of the most extensive and comprehensive research programs in the history of dentistry. There is a logical procedure for such a program. First, the safety of the instrument must be established. Secondly, techniques of use should be developed and taught to the members of the profession. Since energy is used in many aspects of dental service, the widest desirable application of ultrasonics should be explored.