Bending behavior of three NiTi endodontic instruments with different cross-sectional shapes in simulated curved canals
CHEN Lu
CHEN Zao
WU Bu-ling
Abstract：Objective:To compare the stress distribution of three NiTi instruments with different cross-sections during shaping of simulated curved canal, and to study the influence of the cross-sectional geometry on bending behavior of NiTi endodontic instruments, providing reference evidences for clinical applications.Methods:Three NiTi files (ProFile, ProTa-per and ProTaper Universal) were scanned using Micro-CT to produce a three-dimensional digital and finite element model, and the nonlinear, stress-strain behavior of NiTi materials was also evaluated. The bending behavior of the instruments dur-ing shaping of simulated curved canal was calculated mathematically.Results:ProTaper, with a convex trianglar cross-sec-tion, showed the highest Max. von Mises stress of 1426mpa, while the U-shaped ProFile showed the lowest bending stress of 1268mpa. The concentration of stresses were mainly observed at the cutting edge in ProTaper and ProTaper Universal and the bottom of the flutes in ProFile.Conclusions:The cross-sectional profile has a significant influence on the bending behavior of NiTi endodontic instruments. Incorporating a U-shaped groove design increases the flexibility of ProTaper Uni-versal. ProFile might be more suitable for use in the curved canals, while ProTaper is not recommended.
Keywords：NiTi endodontic instrumentcross-sectional geometrybending behaviorstress distribution
Publication Date：2014-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：4( 321-324 )