Abstract
The second proposed variant of the design of the ultrasonic end for removing the damaged screw fixing the prosthetic replacement. The design is specific with a narrower shaft above the working part, the termination of the outlets for cooling higher above the preparation site - just below the anti-rotation element.
The cooling is similarly effective, the thinner shaft then allows a freer passage through the mounting channel without contact with it and therefore the expected better transmission of vibrations to the end part of the tool.