The chisel edge of the SafeSider allowing faster advancement with less resistance. A series of non-circular, non-interrupted flat sided instruments designed to reduce endodontic stress. The flat side reduces instrument engagement allowing faster advancement with less resistance. Reduced binding with increased flexibility. Creates space for dentinal debris that would otherwise clog thread lines of conventional reamers and files. Reduces compressive and tensile stresses during use enabling improved instrument durability and increased flexibility without sacrificing strength.