A numerical method for predicting the bending fatigue life of NiTi and stainless steel root canal instruments

Int Endod J. 2011 Apr;44(4):357-61. doi: 10.1111/j.1365-2591.2010.01838.x. Epub 2011 Jan 10.

Abstract

Aim: To evaluate the bending fatigue lifetime of nickel-titanium alloy (NiTi) and stainless steel (SS) endodontic files using finite element analysis.

Methodology: The strain-life approach was adopted and two theoretical geometry profiles, the triangular (TR) and the square cross-sections, were considered. Both low-cycle fatigue (LCF) lifetime and high-cycle fatigue (HCF) lifetime were evaluated.

Results: The bending fatigue behaviour was affected by the material property and the cross-sectional configuration of the instrument. Both the cross-section factor and material property had a substantial impact on fatigue lifetime. The NiTi material and TR geometry profiles were associated with better fatigue resistance than that of SS and square cross-sections.

Conclusions: Within the limitations of this study, finite element models were established for endodontic files to prejudge their fatigue lifetime, a tool that would be useful for dentist to prevent premature fatigue fracture of endodontic files.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Dental Alloys*
  • Dental Instruments*
  • Dental Stress Analysis / methods*
  • Equipment Design
  • Equipment Failure
  • Finite Element Analysis*
  • Nickel*
  • Pliability
  • Root Canal Preparation / instrumentation*
  • Stainless Steel
  • Titanium*
  • Torque

Substances

  • Dental Alloys
  • titanium nickelide
  • Stainless Steel
  • Nickel
  • Titanium