(PR103) Micro-Computed Tomographic Evaluation of the Shaping Ability of Vortex Blue and TruNatomyTM Ni-Ti Rotary Systems.

The aim was to assess and evaluate the root canal shaping ability of two different Ni-Ti rotary systems, Vortex Blue (VB) and TruNatomy (TN), using micro-computed tomography on extracted human premolars. A total of 20 extracted bifurcated maxillary first premolars with two separate buccal and palatal canals were randomly divided into two groups and prepared with either Vortex Blue 35/0.04 (PTN; Dentsply Maillefer, Ballaigues, Switzerland) or Medium 36/0.03 (TN; Dentsply Sirona). Pre- and post-instrumentation Micro-CT scans were analyzed to measure the following parameters: percentage of touches and untouched canal surface area, dentin thickness, transportation, centering ability, canal volume, structural model index (SMI), and canal angulation. Statistical analysis was done with a significance level set P-value <0.05. Both Vortex Blue and TruNatomy files produced a significant increase in the basic canal geometry parameters, including canal surface area and canal volume. Changes in SMI and dentin thickness after instrumentation were not significant (P>0.05). Some degree of canal transportation and a similar centering ability ratio were observed in both file systems with no significant difference (P>0.05). TN files showed less pre-cervical dentin removal when compared to VB files. A significant difference was found in TN group regarding the dentin removal between coronal and apical thirds (P=0.03). Both Vortex Blue and TruNatomy files produced comparable root canal preparation with no considerable shaping mishaps or errors. Both files showed minimum canal transportation and minimum straightening of the canal curvature. TN files removed less pre-cervical dentin than apical dentin.