The ideal supplement to every Endo sequence is the S-Apex is a NiTi rotary instrument with inverted taper provides greater safety in high curvature, sclerosed or narrow canals. S-Apex instruments are used after access preparation with PreRace tools Pass the first S-Apex instrument ISO 15 as far as the apex, then sequentially the following sizes until the desired size for the final preparation. Finally, it creates an “apical stop”, permitting effective and reliable obturation. It caters to penetration of irrigant and disinfectant solutions up to the apex. Once breaking limit has been passed, because of its inverted taper (ISO diameter D1 > D2) S-Apex will break or bend at its safety point, which is, 16mm from the tip. The piece that has been broken can easily be removed from the canal using tweezers because of the special anti-screwing design which stops any permanent fixation or blockage even in curved and narrow canals.