Related Experiment Video
Updated: Dec 4, 2025
Scanning Electron Microscopic Evaluation of Surface Defects of Remover Retreatment File After Single and Multiple Uses
Published on: October 11, 2024
Numeric Evaluation of Innovate Spring Machined Nickel-Titanium Rotary Instruments: A 3-dimensional Finite Element
Na Yoon Kim1, Sang Won Kwak1, Tae Ho Yoon2
1Department of Conservative Dentistry, School of Dentistry, Dental Research Institute, Pusan National University, Yangsan, South Korea.
Introduction:
The purpose of this study was to investigate if machined springs in nickel-titanium (NiTi) rotary instruments can improve their mechanical properties. The bending and torsion properties were assessed using finite element (FE) model analysis.
Methods:
A basic 3-dimensional file model without a spring was created with apical size #25, 25-mm full length, and 16-mm cutting flutes. Three other models were created with a spring machined into their shaft portion with different numbers of spring coils: standard (STspr), 10% more (INspr), and 10% less (DEspr). To compare the mechanical responses among the 4 FE models, file bending and torsion were simulated using FE analysis.
Results:
Spring machined NiTi rotary instruments showed higher torsional resistance and less bending stiffness than the same instrument without. The spring machined models required more torque to bend or rotate the DEspr model than was required for the STspr and INspr models; however, the STSpr and INSpr models were similar.
Conclusions:
Within the limitations of this study, the FE analysis indicated that machining a spring into the shaft of NiTi rotary instruments improved torsional resistance and bending flexibility. Therefore, spring machining has the potential to increase the durability of the NiTi rotary instruments.
More Related Videos
06:48Rapid Formation and Testing of Self-expanding NiTi Frames with a Small Form Factor Suitable for Minimally Invasive Implants
Published on: March 7, 2025
11:28A Coupled Experiment-finite Element Modeling Methodology for Assessing High Strain Rate Mechanical Response of Soft Biomaterials
Published on: May 18, 2015