Quantitative Transportation Assessment in Simulated Curved Canals Prepared with an Adaptive Movement System

Introduction: The aim of this study was to evaluate the ability of the Twisted File Adaptive (TF Adaptive; SybronEndo, Orange, CA) system in maintaining the original profile of root canal anatomy. The Pro Taper Universal (Dentsply Maillefer, Ballaigues, Switzerland) and Twisted File (TF) (SybronEndo) systems were used as reference techniques for comparison. Methods: Thirty simulated curved root canals manufactured in clear resin blocks were randomly assigned to 3 groups (n = 10) according to the instrumentation system: IF in rotary motion, TF in TF Adaptive motion, and Pro Taper Universal. Color stereomicroscopic images from each block were taken exactly at the same position before and after instrumentation. All image processing and data analysis were performed with an open-source program (Fiji). Evaluation of canal transportation was obtained for 2 independent canal regions: straight and curved levels. Univariate analysis of variance and Tukey Honestly Significant Difference were used, and a cutoff for significance was set at alpha = 5%. Results: Instrumentation systems significantly influenced canal transportation (P = .000). A significant interaction between instrumentation system and root canal level (P = .000) was also found as follows: at the straight part, TF and TF Adaptive systems produced similar canal transportation, which was significantly lower than for the ProTaper Universal system; at the curved part, TF resulted in the lowest canal transportation followed by TF Adaptive and ProTaper Universal systems. Canal transportation was higher at the curved canal parts (P = .00). Conclusions: The TF in rotary motion produced overall less canal transportation in the curved portion when compared with the others tested systems. The ProTaper Universal system showed the highest canal transportation.