Primary root canal treatment is a definitive treatment with established reports of high clinical and radiographic success rates. Failure of root canal treatment results in an indication for clinical mediation. One of the most common causes of failure is complex root anatomy that has not been effectively cleaned or shaped such that the microbial flora remains in the apical sections of the root canals. Failure to completely remove the previous filling may make adequate disinfection difficult by limiting access of antimicrobial agents to certain areas of the root canal system. Debris can cover areas where residual infection occurs. If bacteria remain in the apical canal, the risk of periradicular inflammation is increased. Say no to plagiarism. Get a tailor-made essay on “Why Violent Video Games Should Not Be Banned”? Get an Original Essay One of the most important considerations, which influences the outcome of retreatment, is the complete removal of the root canal filling material. The effectiveness and precision of reprocessing files in removing filling materials are important factors for successful treatment. The biggest challenge for these retreatment instruments is to accurately follow the anatomy of the canal in order to remove all filling material from the root canal. Various techniques have been proposed for removing filling materials, with most of the more recent ones using rotating nickel-titanium (NiTi). Alternatively, some authors have proposed removing the previous filling material with alternative single-instrument systems originally designed for root canal preparation. In this case, the removal of the filling is carried out simultaneously with the re-instrumentation. Further enlargement could further reduce the amount of residual filling. However, significant enlargement is associated with the risk of canal transport, and this risk must be carefully weighed against the added benefit.11 Regardless of the retreatment technique, many studies have shown that complete removal of canal fillings does not 'is generally not obtained,12 particularly in the apical part of the root canals. Therefore, additional approaches have been suggested to improve the complete removal of filling material. Recently, a new NiTi finishing instrument has been developed with the aim of improving root canal cleaning: the XP-endo Finisher R (FKG Dentaire, La Chaux-de-Fonds, Switzerland), which is a non-conical size #30 made with NiTi MaxWire alloy (Martensite-Austenite Electropolish FleX, FKG Dentaire). Thanks to this special alloy, this instrument takes a straight shape in its martensitic phase, which is obtained below 30° C. However, when placed in the channel at body temperature, it changes to the austenitic phase in which the instrument takes the shape of a spoon. shape in the last 10 mm with a depth of approximately 1.5 mm. When rotating, this instrument reaches a natural diameter of 3mm in the last 10mm. According to the manufacturer, when the tip of the instrument is pressed, the bulb can expand up to 6 mm; when the bulb is compressed, the tip extends up to 6mm. Thus, when the XP-endo instrument is moved up and down 7 to 8 mm inside the canal, the natural constrictions and expansions of the canal will alternately cause the bulb and tip to expand and contract. This causes the instrument to scrape the canal walls and cause turbulence in the irrigating solution. The XP-endo Finisher R instrument has the potential to be applied as an additional procedure.