Objective: This study aims to evaluate the influence of the instrument regarding the apical fit and type of the alloy and the preflaring procedures in the accuracy of Propex Pixi.
Methods: A total of 40 extracted human single-rooted permanent teeth with apical diameters of 200 µm were selected. A #10 K-file was inserted in the root canal until its end could be observed by a dental microscope to obtain the real length (RL). Electronic measurements were performed using Propex Pixi to the apex designation (0.0). Different file alloys (stainless steel [SS] and nickel titanium [NiTi]) and sizes (#10, #15, and #20) were used before and after coronal flaring. Statistical analysis was performed by a factorial analysis of variance (p ≤ 0.05). Results: Results showed that significant differences existed in the measurements of electronic length (EL) owing to coronal flaring and that the EL was closer to the RL. The intraclass correlation coefficient was 0.951, i.e., a significant correlation existed between EL and RL. Furthermore, there were no differences between files with different sizes or alloys.
Conclusion: Under the conditions of this study, Propex Pixi demonstrated adequate precision. Its accuracy was enhanced by preflaring procedures independent of the instrument used (SS or NiTi) and the apical fit.