Evaluation of the Shaping Characteristics of ProTaper Gold, ProTaper NEXT, and Pro Taper Universal in Curved Canals

Introduction: This study evaluated the shaping characteristics of the Pro Taper Gold system (PTG;,Dentsply Maillefer, Ballaigues, Switzerland) and compared it with that of the ProTaper Next (PTN, Dentsply Maillefer) and ProTaper Universal (PTU, Dentsply Maillefer) systems using micro computed tomographic imaging. Methods: Twenty-four mandibular first molars with 2 separate mesial canals were matched anatomically using micro computed tomographic scanning (SkyScan1174v2; Bruker-microCT, Kontich, Belgium) with a voxel size of 19.6 mu m. Canals were prepared with PTG, PTU, or PIN rotary systems to F2 or X2 instruments, respectively, and scanned again. Coregistered images were evaluated for 2- and 3-dimensional morphometric measurements of canal transportation, centering ability, untouched canal walls, and remaining dentin thickness. Data were statistically compared using Kruskal-Wallis and 1-way analysis of variance tests (alpha = 5%). Results: Overall, PTN showed significantly higher percentage values of static voxels than PTG and PTU systems (P < .05). Surface area, perimeter, and minor diameter were higher in the PIG and PTU groups than in the PIN group (P < .05). No difference was observed in form factor, roundness, major diameter, as.pect ratio, or structure model index (P > .05). PTG (0.11 +/- 0.05 mm) and PIN (0.09 +/- 0.05 mm) produced significantly less transportation than PTU (0.14 +/- 0.07 mm) (P < .05), and the percentage decrease in dentin thickness was significantly lower for PTG (22.67 +/- 2.96) and PTN (17.71 +/- 5.93%) (P >= .05) than PTU (29.93 +/- 6.24%) (P < .05). Conclusions: PTG and PTN produced less transportation and maintained more dentin than PTU. PTN had less canal wall contact than PIG and PTU, but all file systems were able to instrument moderately curved mesial root canals of mandibular molars without clinically significant errors.