Shaping Ability Of Nickel-titanium Instruments In Curved Root Canals Preparation

Root canal preparation is one of the most important steps in root canal therapy, creating a continuously tapered funnel and respecting the original shape and curvature of the canal are the ideal preparation, aberrations may occur when instruments used in curved canals, the purpose of this study was to compare the shaping ability of different nickel-titanium instruments in simulated resin curved root canals and extracted teeth.Part 1. Shaping ability of nickel-titanium instruments in simulated resin curved root canals .Objective To compare the shaping ability of different nickel-titanium instruments in simulated resin curved root canals. Methods Simulated resin root canals with two different shapes were selected:one was L-shaped(curvature=40 ° ),another was S-shaped(coronal curvature =30° and apical curvature =20° ), these canals (n=10 in each group)were prepared with hand and rotary nickel-titanium instruments, respectively, canals with two shapes were prepared with hand and rotary stainless steel K files as control, a combination of different instruments were used in S- shaped canals...