Evaluation of retreatment instrument damage after removal of root filling materials
TAN Qing-song
TAO Xiao-ling
PEN Bin
Abstract：AIM:To evaluate the damage of two nickel-titanium retreatment instruments after removal of root filling materials.METHODS:6 sets of ProTaper D and of MtwoR were used to remove the filling materials in ex-tracted anterior teeth root canals.The instruments were examined under stereomicroscope after each removal of root fill-ing material.D2 and R25 files without deformation under stereomicroscope observation were examined under scanning electron microscope (SEM)for the observation of structure change.RESULTS:Deformation of ProTaper D and Mt-woR was found after 6 times of filling material removal obsrved under stereomicroscope.Structural disorder or microc-racks were found under SEM after 5 times of use and the microcracks were found to increase after 7 times of use.D3 and R15 files were easier to deform and fracture than other files.CONCLUSION:It is recommended that the two Nickel-titanium retreatment instruments be used less than 6 times for removal of root canal filling materials.
Keywords：Nickel-titanium retreatment instrumentsdamagestereomicroscopescanning electron microscope
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( 346-349 )