en Endodontics Endodontics Original article Original article <div> <table align="center" hspace="0" vspace="0"> <tbody> <tr> <td style="padding: 0cm 12px; text-align: justify;" valign="top"><span style="font-size:13pt"><span new="" roman="" style="font-family:" times=""><b><span style="font-size:9.0pt"><span style="font-family:" verdana=""><span style="color:#2e74b5">Background and Aim</span></span></span></b><b><span style="font-size:9.0pt"><span style="font-family:" verdana=""><span style="color:#2e74b5">:</span></span></span></b><b> </b><span style="font-size:9.0pt"><span style="font-family:" verdana="">Maintaining the original shape and path of the canal is among the most important criteria for optimal root canal preparation. The aim of this study was to compare the centering ability of F6 SkyTaper and RaCe rotary files in mesiobuccal canals of mandibular molars. &nbsp;</span></span></span></span><br> <span style="font-size:13pt"><span new="" roman="" style="font-family:" times=""><b><span style="font-size:9.0pt"><span style="font-family:" verdana=""><span style="color:#2e74b5">Materials and Methods:</span></span></span></b><span style="font-size:9.0pt"><span style="font-family:" verdana=""> In this experimental study, 30 mesiobuccal canals of extracted human mandibular molars with 25-30-degree curvature were randomly divided into two experimental groups (n=15) of RaCe and F6 SkyTaper. After mounting of the teeth in a putty mold, the distance between the canal walls and the outer surface of the roots in mesial and distal aspects was measured. The measurements were made at 1, 3 and 7 mm from the apex. Initial glide path in the canals was achieved using a # 15 K-file. Then, the canals in group A were prepared by RaCe rotary file #25/6% while the canals in group B were prepared by F6 Sky Taper rotary file #25/6%. Measurements were repeated and the difference between the two measurements was calculated and compared with the Mann-Whitney U test.</span></span></span></span><br> <span style="font-size:13pt"><span new="" roman="" style="font-family:" times=""><b><span style="font-size:9.0pt"><span style="font-family:" verdana=""><span style="color:#2e74b5">Results:</span></span></span></b><span style="font-size:9.0pt"><span style="font-family:" verdana=""> The mean centering ability was 0.72 &plusmn; 0.62 in the RaCe group and 0.95 &plusmn; 1.39 in F6 SkyTaper group. the centrality was better in F6 SkyTaper group (it was closer to 1) but the difference was not statistically significant (P=0.4).</span></span></span></span><br> <span style="font-size:13pt"><span new="" roman="" style="font-family:" times=""><b><span style="font-size:9.0pt"><span style="font-family:" verdana=""><span style="color:#2e74b5">Conclusion:</span></span></span></b> <span lang="EN" style="font-size:9.0pt"><span style="font-family:" verdana="">Both RaCe and F6 SkyTaper rotary systems partially offset the centrality of the root canal system</span></span><span style="font-size:9.0pt"><span style="font-family:" verdana="">. </span></span></span></span></td> </tr> </tbody> </table> </div> <div style="text-align: justify;"></div> Cone-Beam Computed Tomography, Root Canal Preparation, Transportation, Dental Instruments 38 42 http://jrdms.dentaliau.ac.ir/browse.php?a_code=A-10-896-3&slc_lang=en&sid=1 Mahsa Ruhollahi mr.mahsa@ymail.com 100319475328460011378 100319475328460011378 No Endodontics Department, Faculty of Dentistry, Tehran Medical Sciences, Islamic Azad University, Tehran, Iran Ahmadreza Talaeipour 100319475328460011379 100319475328460011379 No Oral and Maxillofacial Radiology Department, Faculty of Dentistry, Tehran Medical Sciences, Islamic Azad University, Tehran, Iran Sohrab Tour Savadkouh s_savadkouhi@yahoo.com 100319475328460011380 100319475328460011380 No Endodontics Department, Faculty of Dentistry, Tehran Medical Sciences, Islamic Azad University, Tehran, Iran Nasrin Roghanizad nr686@yahoo.com 100319475328460011381 000000017677836X Yes Endodontics Department, Faculty of Dentistry, Tehran Medical Sciences, Islamic Azad University, Tehran, Iran