A finite element study on the mechanical behavior of reciprocating endodontic files

• Published in: Brazilian journal of oral sciences Vol. 14; no. 1
• Main Authors: Mohamed I. El-Anwar, Ayman O. Mandorah, Salah A. Yousief, Tarek A. Soliman, Tarek M. Abd El-Wahab
• Format: Journal Article
• Language: English
• Published: Universidade Estadual de Campinas 01-03-2015
• Subjects: Endodontics; Nickel. Titanium; Stainless steel
• ISSN: 1677-3225
• DOI: 10.20396/bjos.v14i1.8640846

Aim: To evaluate the mechanical behavior of reciprocating endodontic files, comparing nickeltitanium (NiTi) and stainless steel 316L (St.St. 316L) as manufacturing material for such instruments. Methods: A three-dimensional finite element model was designed for this study. The simplified instrument model geometry was created on commercial CAD/CAM software. Real strain stress curves of St.St. 316L and NiTi were used in the analysis. Non-linear static analysis was performed to simulate the instrument inside root canal at an angle of 45° in the apical portion, and subjected to torsion of 0.3 N.cm. Results: Non-linear NiTi material showed super elasticity and high functionality in such applications. Very high levels of stress appeared in the file at 3 mm from the tip close to yield point. Conclusions: St. St. 316L is not suitable for manufacturing reciprocating instruments. Modeling of the instrument with equivalent circular cross-sectional area did not affect results quality. Reciprocating instruments have short lifespan, thus manufacturers recommend using one file per tooth. Reciprocating instruments are recommended for less experienced dentist.