Abstract: An endodontic tool has a working tip including two cylindrical segments connected together lengthwise and terminating in a conical tip. The cylindrical segment which connects directly to the conical tip is smaller in diameter than the second cylindrical segment, whereby a shoulder is provided at the intersection of the two cylindrical segments. The conical tip and first cylindrical segment have surfaces for removing tooth material when the tool is vibrated at sonic frequencies. A stem connects to the second cylindrical segment at a right angle and is connectable to a conventional sonic hand piece so that vibratory energy generated within the hand piece is transmitted to the working tip by way of the stem. The hand piece provides vibratory motion generally along its longitudinal axis, and the stem is received in the hand piece with the stem axis at an angle to the longitudinal axis of the hand piece.