Shaping Ability of Protaper Gold and Protaper Ultimate in Simulated Root Canals: A Comparative Study

Abstract

This study aimed to compare the shaping ability of ProTaper Gold (PTG) and the newly developed ProTaper Ultimate (PTU) systems in artificial S-shaped canals. Both files are manufactured via gold thermal treatment methods and have variable taper along their working part. Thirty-Two S-shaped canals in clear resin blocks were prepared up to an apical size of 25 using PTU and PTG instruments (n = 16 canals/group). Resin blocks were filled with ink and photographed before & after instrumentation to develop composite images by superimposition. The amount of removed resin was measured perpendicularly to the canal surface in 18 points, in addition to the canal transportation and centering ratio. Statistical analysis was performed by using Manne-Whitney U-test (α = 0.05). No broken files or aberrations were recorded during instrumentation. PTG significantly removed a higher amount of resin at 4, 6, 8, and 9 mm from the apex, but at 1 mm PTU significantly cut a higher amount (p < 0.05). Concerning transportation & centering ability, both files deviated from the center and at 3 mm PTU yielded significantly higher deviation, while at 4 mm PTG recorded a higher value (p < 0.05). In conclusion, PTU produced more conservative preparation than PTG especially in the coronal third, while for maintaining the original canal curve, PTG caused lesser deviation at the beginning of the apical curvature.