Purpose: to compare canal transportation and centering ability of 2 rotary nickel-titanium (NiTi) systems (Twisted Files
[TF] and Pathfile-ProTaper [PP]) with conventional stainless steel K-files.N= 24 mandibular molars with C-shaped canals.
N= 90 Root canals (severe curvature and short radius).
-Divided randomly into 3 groups of 30 each.
-Prepared with TF, PP, and stainless steel files.
-And the amount of transportation that occurred was assessed by using computed tomography (apical, mid-root, and coronal levels recorded ).
-Amount of transportation and centering ability were assessed.
Most highlighted Results:
Less transportation and better centering ability occurred with TF rotary instruments (P < .0001).
(less transportation) TF > PP > K files (highest transportation).
The TF system was found to be the best in term centrality and less transportation.