Related Experiment Video
Updated: May 23, 2026
Scanning Electron Microscopic Evaluation of Surface Defects of Remover Retreatment File After Single and Multiple Uses
Published on: October 11, 2024
Effect of nitrogen ion implantation on the flexibility of rotary nickel-titanium instruments
Marcelo dos Santos1, Giulio Gavini, Evandro Luiz Siqueira
1Discipline of Endodontics, Department of Esthetic Dentistry, School of Dentistry, Universidade de São Paulo, São Paulo, São Paulo, Brazil.
Introduction:
The aim of this study was to assess the effect of nitrogen ion implantation on the flexibility of rotary nickel-titanium (NiTi) instruments as measured by the load required to bend implanted and nonimplanted instruments at a 30° angle.
Methods:
Thirty K3 files, size #40, 0.02 taper and 25-mm length, were allocated into 2 groups as follows: group A, 15 files exposed to nitrogen ion implantation at a dose of 2.5 × 10(17) ions/cm(2), voltage 200 KeV, current density 1 μA/cm(2), temperature 130°C, and vacuum conditions of 10 × 10(-6) mm Hg for 6 hours; and group B, 15 nonimplanted files. One extra file was used for process control. All instruments were subjected to bend testing on a modified troptometer, with measurement of the load required for flexure to an angle of 30°. The Mann-Whitney U test was used for statistical analysis. Findings with P <.05 were considered significant.
Results:
The mean load required to bend instruments at a 30° angle was 376.26 g for implanted instruments and 383.78 g for nonimplanted instruments. The difference was not statistically significant.
Conclusions:
Our findings show that nitrogen ion implantation has no appreciable effect on the flexibility of NiTi instruments.
