Using Cone-Beam Computed Tomography to Evaluate Shaping, Transportation, and Dentin Thickness in Mandibular First Molars Prepared with Four Different NiTi Rotary Systems

Abstract

Aim: The main aim of this ex vivo study was to evaluate the shaping characteristics and compare the transportation of the apical foramen along with the residual dentin thickness in the mesial curved canals of mandibular molars using Cone-Beam Computed Tomography (CBCT). The study evaluated four Nickel-Titanium (NiTi) instrumentation systems: Neoendo Flex Rotary File, Bondent UDG CC Platinum V.EU, Gen Endo ColteneWhaledentPvt. Ltd, and Mani Jizai.

Methods: An ex vivo study was conducted on freshly extracted human permanent mandibular first molars with mature apices. The root canals were prepared using a crown-down technique in mesial canals of mandibular first molars. After instrumentation, the canals were rinsed with a 17% EDTA solution and then with sterile saline. The transportation and residual dentin thickness were evaluated using CBCT before and after instrumentation. Statistical analysis was performed using SPSS version 23.0, and the results were analyzed with a p-value less than 0.05 being considered significant.

Results: The mean transportation was significantly less with the Gen Endo files, which showed a p-value of <0.001. The maximum mean transportation value was observed for Neo Endo files. The measured curvature angles showed greater variability with NeoEndo and Bondent, while GenEndo and Mani Jizai demonstrated more consistent shaping. GenEndo and Mani Jizai files resulted in a significantly higher average canal area after instrumentation, suggesting they made better contact with the canal walls and provided more effective cleaning and shaping.

Conclusion: The findings suggest that while all tested files are effective, Gen Endo files exhibited significantly less transportation. GenEndo and Mani Jizai files demonstrated more consistent shaping and greater effective cleaning of the canal walls.