Comparative Analysis of Rotary Systems in Curved Root Canals: Evaluation of Wear, Transportation, and Centering Capacity

<b>Background/Objectives:</b> Root canal instrumentation has a crucial role in the success of endodontic treatment. However, management of curved root canals remains a challenge. This study aimed to compare the performance of four rotatory file systems, ProTaper Next, TruNatomy, ProTaper Ultimate and Race Evo, in terms of wear, transportation and centering capacity, in curved root canals. <b>Methods:</b> A total of 150 human tooth roots were selected, divided based on the degree of curvature, and then distributed into four experimental groups according to the rotary system used. Cone beam computed tomography images were obtained before and after instrumentation, and values were measured with ImageJ software. <b>Results:</b> Regarding root canal wear, the TruNatomy system displayed the lowest wear values, and the Race Evo system showed a tendency for greater wear. For transportation, TruNatomy and Race Evo had the lowest transportation, indicating a higher respect for the root canal's original anatomy. For centering ability, Race Evo and ProTaper Ultimate displayed values closer to perfect centering compared to other systems. <b>Conclusions:</b> Overall, TruNatomy was confirmed as a more conservative system, Race Evo with a tendency for greater wear even though with a higher respect for root canal original anatomy. Race Evo and ProTaper Ultimate showed better centering ability.