Patent ID: 11504211

Abstract:
Provided is a dental file with excellent flexibility, cutting performance, and fracture resistance. The dental file (10) of the present invention has a spiral working portion (11) of which cross sections become smaller toward a tip end. At least one of shapes of the cross sections of the working portion (11) is a substantially rectangular shape formed of a single arc (40) and three lines (41, 42, 43), Two points of four points at four corners of the substantially rectangular shape are arranged on a virtual circle (50), which includes the arc (40) as part thereof. The other two points are arranged inside the virtual circle (50). The center position of the virtual circle (50) is inside the substantially rectangular shape. A shortest one of lengths of perpendicular lines each extending from the center position of the virtual circle (50) including the arc (40) as part thereof to the three lines (41, 42, 43) is equal to or greater than 45% and equal to or less than 65% of the radius of the virtual circle (50).