Iranian Dental Association Journal of Iranian Dental Association 3060-8201 17 3 2005 06 01 A comparison of transportation and time of canal preparation with stainless steel hand instruments and Ni-Ti rotary systems (In – Vitro) 88 94 EN Mohammad reza Sharifian Mohammad hossein Nekoofar Poria Motahari Azadeh Tavakoli Journal Article 2007 05 07 2013 02 25 A comparison of transportation and time of canal preparation with stainless steel hand instruments and Ni-Ti rotary systems (In – Vitro) Dr. MR. Sharifian* - Dr. MH. Nekoofar* - Dr. P. Motahari** - Dr. A. Tavakoli*** *-Assistant Professor of Endodontics Dept. – Faculty of Dentistry – Tehran University of Medical Sciences. **- Assistant Professor of Oral and Maxillofacial Pathology Dept. – Faculty of Medicine – Tehran University of Medical Sciences. ***- Dentist. Background and Aim: Canal preparation, as a basis for a successful endodontic treatment, is a big challenge in curved canals. The aim of this study was to evaluate canal transplantation and time of its preparation with stainless steel hand instrument (k – Type) and Ni-Ti rotary systems: Profile and Hero 642. Materials and Methods: In this interventional study, forty – two extracted curved (20-50) human mandibular molars were divided into three groups. Canal preparations were performed with stainless steel hand instruments and Ni-Ti rotary systems: profile and Hero 642. Pre and post instrumentation radiographic images were superimposed. Mercury was injected pre and post instrumentation for canal shape recognition. A computer – based software (Corel Draw 7) was used for the analysis of canal transportation. Time of canal preparation was also recorded. Data was subjected to ANOVA statistical test. Results: Stainless steel hand instrument (k – Type) shaped significantly greater canal transportation both mesiodistally and buccolingually than profile and Hero642 (P<0.05). Time of canal preparation with Ni-Ti rotary systems was significantly less than that of hand file (P<0.05). Conclusion: Canal transportation and time of canal preparation in Ni-Ti rotary systems were significantly less than stainless steel hand fileKey words: Canal transportation – Hand file – Stainless steel – Rotary file – (Ni-Ti) – Time of canal preparation.