Comparison of cutting efficiency and shaping ability of different nickel titanium rotary instruments

Aim: The aim of this study is to compare the cutting efficiency and shaping abilities of different nickel titanium rotary systems. Material and Method: TruNatomyTM (Dentsply Maillefer, Ballaigues, Switzerland), VDW. ROTATETM (VDW, Munich, Germany), Endostar E3 Azure (Poldent, Warsaw, Poland), EdgeFile® X3/X7 (EdgeEndo, Albuquerque, NM, USA) rotary systems with different heat treatments were divided into 4 groups of n=12; their cutting efficiency was evaluated on plexiglass specimens in the lateral axis by applying 150 grams of free weight, and their shaping ability was evaluated on J-shaped artificial root canals with a 70° angle of curvature at the recommended speed and torque values of each rotary system. Plexiglass specimens and clear resin blocks were digitally imaged, and measurements were made on the specimens using Adobe Photoshop 2022 (Adobe, San Jose, CA, USA) image processing software. The findings were transferred to the statistical program SPSS 25.0 (IBM, Chicago, IL, USA) and evaluated using one-way analysis of variance (One- Way ANOVA) and Post-Hoc Tukey's HSD tests. Results: In terms of cutting efficiency, the EdgeFile® X3 C2 rotary instrument cut significantly more area and depth than the other rotary instruments (p<0.05). When shaping ability was evaluated, it was found that the TruNatomyTM rotary system removed less resin than the other rotary systems; the EdgeFile® X7 rotary system caused transportation, especially in the middle area of the canal, and had a lower canal-centering ratio than the TruNatomyTM rotary system (p<0.05). Conclusion: It was concluded that Fire-Wire alloy, which provides high cutting efficiency to rotary instruments, can cause procedural errors such as transportation and strip perforation during shaping in clinical use, and that the TruNatomyTM rotary system can be safely used for shaping curved canals. Keywords: Endodontics, cutting efficiency, shaping ability, nickel titanium