Differences in Niti and Glide Path Rotary System: Preparation of Canal Centering and Transportation in Double-curved Root Canals

Background The primary goal of root canal preparation is to eliminate infected pulp and necrotic tissue within the root canal to facilitate the healing of periapical lesions. Shaping and cleaning are critical success factors in endodontic treatment. The complexity of root canal anatomy makes shaping difficult, which raises the risk of procedural errors and insufficient disinfection. Objective This study aimed to evaluate the differences between Niti rotary systems with glide paths on centering and transportation of double-curved root canals. Methods Thirty-six stained double-curve resin root canal samples were divided into six groups (n=6), Proglider+M3 Pro Gold, Proglider+Protaper Gold, Proglider+Protaper Ultimate, Protaper Slider+M3 Pro Gold, Protaper Slider+Protaper Gold, and Protaper Slider+Protaper Ultimate. Glide paths were created using ProGlider (PG) and ProTaper Slider (PS) prior to further preparation to an apical size of 25, using three different rotary continuous systems: M3 Pro Gold (M3PG), ProTaper Gold (PTG), and ProTaper Ultimate (PTUlt). Images were taken before and after treatment for superimposition. Measurements were taken using concentric circles at 1 mm intervals. Perpendicular lines were drawn from the prepared surface to define ten measurement points. Results Significant differences in centering ability were observed at points 2 and 6 ( p < 0.05). At point 2, significant differences were found between the PG+M3PG group and the PG+PTUlt group, as well as between the PG+PTUlt group and the PS+M3PG group. At point 6, significant differences were observed between the PG+PTUlt group and the PS+M3PG group. Significant differences in canal transportation were found at points 0, 2, and 9 ( p < 0.05). At point 2, significant differences were found between the PG+M3PG group and the PG+PTUlt group, as well as between the PG+PTUlt group and the PS+M3PG group. At point 9, significant differences were observed between the PG+M3PG group and the PG+PTUlt group. All systems exhibited canal transportation, and none demonstrated perfect centering ability. Conclusion The Protaper Slider+M3 Pro Gold combination showed better centering ability compared to Proglider+Protaper Ultimate in two-thirds of the root canal. When used with ProGlider, the M3 Pro Gold system demonstrated better prevention of canal transportation in the apical third compared to ProTaper Ultimate but showed inferior performance in the coronal third. M3 Pro Gold can be a good choice in curved root canals, while both Protaper Gold and Protaper Ultimate can be a good choice in straight root canals or calcified root canals.