Shaping ability of different file systems in simulated s-shaped root canals

Purpose: The aim of this study was to compare the shaping efficiency of three different new file systems on S-shaped resin blocks. Method: 39 S-shaped resin blocks were divided into groups according to 3 different file systems to be used for shaping. In each group, 13 resin blocks were shaped with ProTaper Ultimate (F2), R Motion (25) and XP Endo Rise Shaper file systems. Canal transport in the right-left and anteroposterior directions, ability to remain centered, and procedural errors were calculated by measuring the amount of material removed from four different directions by overlapping the photographs taken before and after shaping. Shaping time was also measured. Friedman S Two-Way Variance test was used to analyze the data and Bonferroni (Dunn) test was used to determine the differences between group means (P<0.05). Results: There was a significant difference between the groups in terms of canal transport only in the coronal slope region for the right-left direction (p<0.001). In all file systems, the direction of transport was to the inner surface of the coronal bevel. The least transport was observed in the R Motion file group (p<0.001). In terms of the ability to stay in the center, there was a difference between the groups in the coronal flat region (p<0.05) and the XP Endo Rise Shaper file group was found to have the lowest ability to stay in the center. For the anteroposterior direction, there was a significant difference between the groups in terms of canal transport only in the coronal flat and coronal slope regions (p<0.05). The ProTaper Ultimate file group had the highest transport. In terms of the ability to stay in the center, there was a difference between the groups in the coronal flat and coronal slope regions (p<0.05) and the XP Endo Rise Shaper file group was found to have the lowest ability to stay in the center. Apical trasportation was observed in 1 specimen in the Protaper Ultimate group, in 2 specimens in the R Motion Group and in 2 specimens in the XP Endo Rise Shaper group. XP Endo Rise Shaper was the fastest shaping file (p<0.05). Conclusions: In S-shaped resin blocks, canal transportation is more common in the coronal slope and coronal flatness, and in this respect, the R Motion (25) file is more successful than XP ENdo Rice and ProTaper Ultimate files. In terms of its ability to stay in the center, the XP Endo Rise Shaper file is less successful than the other file systems compared. Keywords: S-shaped canal, shaping ability, resin block, ProTaper Ultimate, R Motion, XP Endo Rise Shaper