[PROBLEMS] is provided in the sound dentine in transfer stainless steel bar or even minute asperities portion, as needed, can be by sensed cutting dentine by doctor. [MEANS FOR SOLVING PROBLEMS] a handle part (11) are coupled, side is provided with removably handheld component proximal end, there is working portion (12) edge to provide for cutting tooth in distal end, tapered intermediate portion (13) connection operation portion and handle portion. Reinforcing bar is that have fibre structure by drawing to processing hardening austenitic stainless steel is carried out. Vibration is generated since tapering is bent, when sound dentine cuts through rotation work part, the sound for cutting dentine can identify and can prevent from being cut too much with sound dentine. Optionally, that perfects dentine is cut too many etching, can prevent the sound dentine for deteriorating acutance whereby compared to maximum gauge part and rounded edges by distal end working portion.
