Micro-Computed Tomographic Evaluation of the Shaping Ability of Vortex Blue and TruNatomyTM Ni-Ti Rotary Systems

Abstract Aim: To assess and evaluate the canal shaping ability of two different Ni-Ti rotary systems ex-vivo: Vortex Blue (VB) and TruNatomy (TN), using micro-computed tomography (micro-CT) in extracted premolar human teeth. Materials and Methods: A total of 20 extracted bifurcated maxillary first premolars with two separate buccal and palatal canals wererandomly divided into two groups and prepared with either Vortex Blue or TruNatomy files. All teeth were scanned by micro-CT before and after root canal preparations. The micro-CT scans were analyzed to measure the following parameters: percentage of untouched canal surface area, changes in canal surface area, changes in canal volume, structural model index (SMI), changes in canal angulation and changes in dentin thickness. Statistical analysis was conducted to compare the means and standard deviations of the parameters between the two systems, with statistical significance level set at P -value < 0.05. Results: Both VB and TN files exhibited a significant increase in the basic canal geometry parameters including canal surface area and canal volume after canal instrumentation with no statistical significant differences between both files and with no considerable shaping mishaps or errors. Both file systems showed no significant changes in the SMI and dentin thickness after canal instrumentation. TN files demonstrated less straightening of the canal curvature compared to VB files with no statistically significant difference. Furthermore, TN files showed less cervical dentin removal when compared to VB files with no significant difference. A significant difference was found in TN group regarding dentin removal between coronal and apical thirds. Conclusion: Vortex Blue and TruNatomy files produced comparable root canal preparation with no considerable shaping mishaps or errors. Both files induced minimal canal straightening after preparation. TN files resulted in less removal of cervical dentin compared to apical dentin.