Relation between laboratory cantilever bending test and finite element analysis of five different nickel-titanium rotary instruments

Abstract

Abstract Background Flexibility during bending is a critical feature that influences the performance and safety of endodontic nickel-titanium rotary instruments. Flexibility of the endodontic files could be assessed via laboratory test or indicated theoretically by finite element analysis (FEA). The aim of the study is to determine the cantilever load required for bending five different nickel-titanium (NiTi) rotary instruments (laboratory test) and to calculate maximum von Mises stresses due to bending moment and vertical displacement (deflection) (theoretically by FEA) and compare both results. Results TF Adaptive file demonstrates the least cantilever load required for bending, the least von Mises stresses generated and the highest deflection of the endodontic files. Contrary, One Shape file reported the highest cantilever load required for bending, the highest von Mises stresses generated and the least deflection among all the tested endodontic files. Conclusion The finite element analysis validated the results of the laboratory cantilever bending test for the examined nickel-titanium rotary instruments.

Keywords

• Rotary files
• NiTi
• Design
• Stress distribution
• Bending
• Flexibility