الفهرس 
Geometric analysis of curved canals prepared by HyFlex EDM versus HyFlex CM Rotary Nickel Titanium files (An in-vitro study)Only 14 pages are availabe for public view
 |  | from | 166 |  |  |
| | | from | 166 | | |
Abstract
Aim: The aim of this study was to evaluate and compare 2 file systems; HyFlex EDM and HyFlex CM in preparing severely curved mesiobuccal canals of human mandibular molars regarding: transportation of the canal, the centering ability and change of radius of canal curvature, using cone beam computed tomography (CBCT) scanning.Materials and methods: A total of thirty mesiobuccal root canals of natural extracted human mandibular molars with the angle of curvature ranging from 25-45 {u0366} (according to Schneider) were selected and assigned into two equal groups; HyFlex EDM and HyFlex CM. After access cavities preparation and working length determination, the distal roots with the respective part of the crowns of all samples were sectioned at the furcation level and discarded. Samples were mounted in two acrylic resin molds for pre-instrumentation imaging using CBCT. Root canal preparation was done according to the manufacturers’ instructions of each NiTi system. The post-instrumentation imaging using CBCT was done with the same parameters of pre-instrumentation imaging.The pre and post-instrumentation CBCT images were superimposed using a fusion module of OnDemand 3D App software to measure the dentin thickness at the determined root canal levels (3, 5 and 8 mm from the tooth apex). Canal transportation and centering ability were recorded according to formula introduced by Gambill et al, while the change in the radius of canal curvature was recorded following Estrela et al. Data was tabulated and statistically analyzed