DENTAL FILE

A dental file includes a working portion having a spiral shape, wherein a cross section perpendicular to a longitudinal direction of the working portion has a trapezoidal shape including an upper bottom, a lower bottom, and first and second oblique sides, vertexes at both ends of the lower bottom are located on an imaginary circle having a center at an axis in the longitudinal direction of the working portion, vertexes at both ends of the upper bottom are located inside the imaginary circle, and the imaginary circle has a diameter decreasing from a base end portion toward a leading end portion of the working portion. 本发明提供一种牙科用锉，具有形成为螺旋状的作业部，所述作业部的与长边方向垂直的截面的截面形状为具有上底、下底、第一斜边以及第二斜边的梯形形状，所述下底的两端的顶点位于以所述长边方向的轴心为中心的假想圆上，并且，所述上底的两端的顶点位于比所述假想圆靠内侧的位置，并且，所述假想圆具有从所述作业部的基端部到前端部变小的直径。