Evaluation of cyclic fatigue in three pediatric endodontic rotary file systems in root canals of primary molars: A finite element analysis (FEA).

Abstract

<h4>Objective</h4>The aim of this study was to evaluate the cyclic fatigue resistance of three different pediatric endodontic rotary files in the root canals of primary molars using finite element analysis (FEA). The research focuses on understanding the mechanical behavior of the files under varying canal curvatures to determine their suitability for pediatric endodontics.<h4>Methods</h4>Finite Element Analysis (FEA) was utilized to simulate cyclic fatigue performance in primary molar canals with curvatures of 30°, 60°, and 90°. The rotary files made up of nickel-titanium (NiTi) alloys included in this study were Kedo SG, Neoendo Pedo Flex, and Pro AF Baby. Stress distribution, maximum stress values, and cyclic fatigue resistance were evaluated to identify differences in performance. Simulations were conducted under controlled conditions to model real-world clinical scenarios. Stress distribution and the number of cycles until failure were analyzed using Goodman's fatigue model and the S-N curve.<h4>Results</h4>The Pro AF Baby files exhibited the highest cyclic fatigue resistance and the more favourable stress distribution across all canal profiles, due to its triangular cross-sectional geometry. Whereas, Kedo SG and Neoendo Pedo Flex demonstrated higher stress levels and lower fatigue life, particularly in severe curvatures (90°), indicating increased susceptibility to failure. Elevated stress concentrations were observed near the apical tip, correlating with reduced fatigue life as canal curvature increased.<h4>Conclusion</h4>Pro AF Baby B2 demonstrated better fatigue resistance and safety for endodontic procedures in primary molars with complex root canal curvatures. These findings emphasize the importance of material properties and file design in improving clinical outcomes. Future research should focus on long-term clinical validation and further optimization of rotary file systems for pediatric dentistry.