The shaping ability of two rotary nickel titanium instruments compared to stainless steel hand instruments in curved root canals

Abstract EN

Objectives : This study was conducted to compare the shaping ability of two rotary nickel-titanium instruments (Hero Shaper and RaCe) and stainless steel hand instrument (k-fiexofilc) in curved root canals of extracted human teeth.

Materials and Methods : A total number of 60 mesial roots of extracted human lower molar teeth with angle of curvature ranging from 20° to 40° according to Schneider’s method were used for the study.

Root canals were divided into three equal groups according to the instrument used for root canal preparation: Group I : Root canals instrumented with Race rotary instrument.

Group II : Root canals instrumented with Hero Shaper rotary instrument.

Group III : Root canals instrumented with hand stainless steel K-flexofile.

The pre-instrumented and post-instrumented radiograghic images were taken in the same standard manner with the digital radiovisiography machine.

The digitized images were then imported into the Autocad 2007 to measure the pre-instrumented and the post-instrumented angle and radius of curvature.

; Results : Race rotary instrument presented the least significant change, while K-flexofile presented the greatest significant change in the angle of curvature in both the buccal and the proximal views.

The mean change between pre-operative and post-operative radii of curvature was statistically significant for the Hero-Shaper and the K-flexofile groups.

However, it wasn’t statistically significant for the RaCe group.

Conclusion : Race rotary instruments maintained the original canal curvature better than Hero Shaper and Hand K-flexofile.