The Endo-Express® Reciprocating Handpiece and the SafeSiders® make rotary irrelevant. Eliminate the fear of fracture associated with crown-down systems and the typical shortcomings of the step-back process. Unlike rotary, reciprocation prevents binding, by engaging dentin only during clockwise rotation. Counterclockwise rotation disengages from the dentin. Excessive force is never needed. Replace instruments because they dull and not because you fear they will break!