Comparative investigation of 2 rotary nickel-titanium instruments: protaper universal versus protaper

ObjectiveThe objective of this study was to evaluate whether the changes in the design of the ProTaper canal instruments contribute to the shaping ability of the instrument in terms of the morphology of curved canals measured by the cross-sectional area using the Bramante method.Study designTen extracted human mandibular molars with root canal curvatures between 25° and 41° were used. Ten mesiobuccal canals were instrumented with ProTaper and 10 mesiolingual canals were instrumented with ProTaper Universal rotary instruments. Pre- and postoperative sections were obtained from the coronal, middle, and apical portions and analyzed. Statistical analysis was performed using the Student t test (P < .05).ResultsNo statistically significant difference was observed in terms of amount of dentin removed, transportation, variation of canal shape factor or change in working length, and working time (P > .05). Only one instrument fracture (F2 in the ProTaper group) and 2 instrument deformations (S1 and F3 in ProTaper and ProTaper Universal, respectively) were noted.ConclusionWithin the limitations of this study, the modifications on ProTaper instruments were found to not create any discrepancy on the shaping abilities of instruments and the evaluated other factors. In addition, both rotary nickel-titanium instruments prepared a well-shaped root canal with minimal canal transportation.