Abstract: A dental percussion instrument, which has a instrument housing fashioned as a handpiece, a ram with a test head at one end being mounted in the housing for movement between a retracted and an extended position and an electromagnetic drive for shifting the ram between said positions, characterized by the ram having essentially a constant cross-section over its entire length, a permanent magnet being secured to the other end of the ram opposite the test head and the magnetic coil of the drive being rigidly situated in the instrument housing in a portion spaced axially from the other end of the ram and the permanent magnet.

Abstract: A percussion instrument suitable for use in dental practice for determining the degree of looseness of a tooth has a ram displacably seated in the handpiece and a means for accelerating the ram from an initial position to a defined velocity, the ram subsequently moving toward a test object in free flight with a constant velocity. The ram is returned to its initial position with the assistance of a magnetic field. The ram is in the form of an elongated oscillating lever having a pivot axis located at its center of gravity, the axis being disposed at a right angle relative to a longitudinal axis of the instrument. The ram has a test head at one end thereof which is disposed at an angle, such as a right angle, with respect to the lever portion of the ram.