# Influence of the Adaptive Torque Control Motion on the Ability of Neolix EDMax to Reach Working Length When Used as a Single Shaping File—An In Vitro Study

## TL;DR

This study examines how a specific motion control system affects the performance of a dental tool in shaping curved root canals.

## Contribution

The study introduces evidence that Adaptive Torque Control motion improves shaping efficiency without needing a pre-established glide path.

## Key findings

- Establishing a glide path improved shaping efficiency compared to no glide path.
- Adaptive Torque Control outperformed the control group in reaching working length without a glide path.
- The motion system effectively shaped double-curved canals without prior glide path preparation.

## Abstract

Objectives: The aim of this study is to investigate how Adaptive Torque Control motion influences the shaping efficiency of Neolix EDMax (Neolix SAS, Évron, France) and its ability to reach working length with or without a pre-existing glide path. Methods: A total of 90 endo training blocks with an S-shape curvature were divided into three groups based on the kinematics and preparation phase: the control group, where the Neolix EDMax (Neolix SAS, Évron, France) was used for shaping after a glide path was established; the no glide path group, where the Neolix EDMax (Neolix SAS, Évron, France) was used for shaping without a glide path; and the Adaptive Torque Control group, where the Neolix EDMax (Neolix SAS, Évron, France) was used for shaping without a glide path but in an Adaptive Torque Control motion. The time for shaping, the instrument passes, and the ability to reach working length were recorded and analyzed using a one-way Anova and Tukey’s HSD post hoc test. Results: Establishing a glide path helped the shaping file to reach working length faster and in fewer passes when compared with the no glide path group, but the Adaptive Torque Control group was able to perform even better than the control group despite not having a pre-established glide path. Conclusions: The Adaptive Torque Control motion on continuous rotation instruments does impact their performance. Combining the efficiency of continuous rotation and the safety of reciprocation, this type of motion had a significant effect on the ability to shape the simulated root canal even in the presence of a double curvature and without a pre-established glide path.