Rectangular Cross Section for Greater Strength Like ProTaper® Universal, PROTAPER NEXT® rotary files feature variable taper performance, but adds an off-centered, rectangular cross section for increased file strength. Unlike ProTaper Universal’s concentric core that creates symmetric rotary motion, PROTAPER NEXT features a patented off-center, rectangular core that adds greater strength as the file tracks down the canal. The patented design’s axis of rotation differs from the center of mass. As a result, only two points of the rectangular cross section touch the canal wall at a time. Unique Asymmetric Rotary Motion for Added Efficiency PROTAPER NEXT’s AR Motion allows you to achieve a fully tapered canal with fewer files. The result is the predictable ProTaper® shape you expect — with greater procedural efficiency.