An ultrasonic handpiece is used for augmenting a bone screw. The handpieces comprise a housing, an ultrasonic converter shiftingly accommodated in the housing, and a sonotrode connected to one end of the ultrasonic converter. The sonotrode protrudes from the housing into the bone screw. An adjuster wheel is adjustably connected to the housing. A spring is provided the ends of which are supported by the ultrasonic converter and the adjuster wheel, respectively. The ultrasonic converter is preloaded in the direction away from the adjuster wheel by setting the adjuster wheel, thereby the sonotrode is urged with a selected force into the bone screw and the augmentation material is pressed out of the bone screw and into the bone.
