Related Experiment Video
Updated: May 5, 2026
Scanning Electron Microscopic Evaluation of Surface Defects of Remover Retreatment File After Single and Multiple Uses
Published on: October 11, 2024
Comparison of first accessory cone penetration after using stainless-steel and ni-ti spreaders in curved resin blocks
Nahid Mohammadzade Akhlaghi1, Nasrin Roghanizad, Zohreh Khalilak
1Department of Endodontic, Dental School of Islamic Azad University and Iranian Center for Endodontic Research, Tehran, Iran.
Introduction:
The purpose of this study was to compare first accessory gutta-percha penetration after the use of nickel-titanium (Ni-Ti) or stainless-steel spreaders in curved resin blocks.
Materials And Methods:
Forty resin blocks with 30º and 45º curvatures (20 blocks for each) were prepared and #30 master cones were placed in canals. In part one, under 20 Newton pressure, Ni-Ti or stainless-steel spreaders were placed alongside the master cone and their penetration was measured with a millimeter ruler. In part two, after removing the spreader, one of the accessory cones (#15, #20 or MF) was substituted in the canal and its penetration was measured. The Mann-U Whitney test was used for the final evaluation.
Results:
In both curvatures, the penetration of Ni-Ti spreaders were significantly more than stainless-steel spreaders (p<0.005). Penetration of the first accessory cones (#15 and MF) in Ni- Ti spreader group were also significantly more than stainless-steel group (p<0.05) (in both curvature groups).
Conclusion:
This study showed that Ni-Ti spreaders and #15 accessory cones penetrated deeper in curved canals than stainless spreaders and #15 accessory cones. Therefore, the use of NiTi spreader in lateral condensation technique is suggested for better results.
