الفهرس 
IntroductionOnly 14 pages are availabe for public view
 |  | from | 101 |  |  |
| | | from | 101 | | |
Abstract
Background : Purpose : The purpose of this study was to compare the shaping ability of different NiTi rotarysystems (WaveOne, ProFile GT Series X, and ProTaper) in extracted human teeth using cone-beamcomputed tomography (CBCT)scanning.Materials and Methods: Forty-five mesiobuccal canals of mandibular molars with angle ofcurvatures between25°─45°degrees,wererandomlydividedinto3experimentalgroups(n=15),accordingtothe NiTi rotary system used, Waveone, GT series X and Protaper groups. Canals were scanned before andafter instrumentation by using CBCT scanner to evaluate root canal transportation and centering ratio at 3, 6,and 9 mm from the apex. Data were statistically analyzed, and the significance level was set at P <.05.Result: GTX system showed significantly less canal transportation and more centering ability, comparedto ProTaperandWaveOnesystems(P<0.05).While,therewasnosignificantdifferenceintheamountof transportation between WaveOne and ProTaper systems. GTX system, also showed significant lymore dentine removal from thein ner wall,at thelevelof3mm,and less dentine removal from the inner wall,at the level of 9 mm from the apex, when compared to ProTaper and WaveOne systems (P <0.05). Conclusion:With in the limit at ion of this study,least canal transportation was produced by GTX system, with evenly dentin removal from canal walls. Further more, GTX in struments main tained the originalcanal curvature in curved canals, better than Pro Taper and Wave One in struments. Recommendation:Long-term research esis still required tode term in etheshaping ability of then ewnickle-titaniumon the curved canal by using the con- beam computed tomography.