Aim of the study: To study the effectiveness of using dental operating microscope
and ultrasonics with Hedstrom files in removing gutta-percha and sealer from root canals.
Materials and Methods: Twenty single straight rooted, extracted human mandib
ular
premolars were prepared, filled with gutta-percha and sealer (Zinc oxide with eugenol).
Specimens were then divided into two groups (N1=N2=10), and root filling material was
removed using H-files with Eucalyptol (group 1); H-files with Eucalyptol, followed by
using microscope with ultrasonic tip (group 2). After retreatment, the efficacy of each
technique was examined at 8× magnification with a stereomicroscope then the images were
analyzed using Auto-CAD 2010 according to Hulsmann and Stotz scale.
Data were statistically analyzed using Mann–Whitney U-tests.
