A disposable ultrasonic handpiece that contains a transducer and a connecting body that is attached to a tube with a cobra work tip at its distal end. The housing that surrounds the ultrasonic transducer does not require waterproofing for repeated autoclaving. Also, the electrical cord that provides power to the transducer is made of very inexpensive wire, along with a low-cost electrical connector. A power cord can be plugged into and unplugged from a socket at the proximal end of the housing and can be reused. Thus, only the housing and its contents need to be disposed of after a procedure, making the disposable part of the handpiece low cost. In addition, the cobra work tip can be provided with a cutting gap that increases its ability to cut.