PROBLEM TO BE SOLVED: To provide a root canal treatment tool capable of reducing fatigue of a dentist and maintaining concentration by making it possible to easily perform operations such as cutting a root canal of a tooth and removing nerves. SOLUTION: A vibration side housing 11 is attached to the tip of a handle side housing 10 to serve as a reciprocating movement generator. The detachable portion 13 of the hand file 4 is reciprocally incorporated in the vibrating side housing 11. The needle portion 41 of the hand file 4 inserted from the attachment port 16 of the hand file 4 at the rear end of the attachment / detachment portion 13 and fixed with the screw lid 3 protrudes forward from the needle through hole 15 of the attachment / detachment portion 13 ( Figure 1). On the other hand, when the hand file 4 is attached to the attachment / detachment portion 13 in the opposite direction and fixed with the screw lid 3, the needle portion 41 projects rearward from the needle through hole 30 of the screw lid 3 (FIG. 4). Since the needle through hole 30 has a longer depth than the needle through hole 15, the length of the protruding needle portion 41 is shorter at the rear. [Selection diagram] Fig. 1【課題】 歯の根管の切削や神経を抜く作業などを楽に行い得るようにすることにより、歯科医師の疲労を少なくして集中力が持続できるような根管治療用具を提供する。【解決手段】 ハンドル側筐体１０の先に振動側筐体１１を取り付けて往復動発生具とする。振動側筐体１１の中にハンドファイル４の着脱部１３を往復動自在に組み込む。着脱部１３の後端部のハンドファイル４の装着口１６から挿着してネジ蓋３で固定されたハンドファイル４はその針部４１が着脱部１３の針通し孔１５から前方に突出する（図１）。これに対してハンドファイル４を逆の向きで着脱部１３に装着してネジ蓋３で固定すると、針部４１はネジ蓋３の針通し孔３０から後方に突出する（図４）。針通し孔１５よりも針通し孔３０の方が奥行きが長いため突出する針部４１の長さは後方が短くなる。【選択図】図１
