title: A comparative study of four rotary NiTi instruments in preserving canal curvature, preparation time and change of working length.
abstract: The purpose of this ex vivo study was to compare working time, working length changes and shaping effects using ProTaper, ProFile, FlexMaster and Mtwo rotary instruments. A total of 96 mesiobuccal roots of the first maxillary molars were prepared using these instruments. Using pre and post-radiographs, canal curvature and working length were measured. In addition, the time required for canal preparation was recorded. Data was statistically analysed using one-way anova and Duncan's post-hoc tests. ProTaper significantly lessened the canal curvature (P < 0.001), and Mtwo rotary instruments took significantly less instrumentation time (P < 0.001). No significant difference was observed between the four groups in changing working lengths (P = 0.081). According to the results of the study, the Mtwo rotary instruments required significantly less instrumentation time, and the ProTaper significantly changed the canal curvature.
authors.affiliation: Endodontics, School of Dentistry, Tehran University, Tehran, Iran. vahidala@sina.tums.ac.ir
authors.forename: Alavieh
authors.initials: A
authors.lastname: Vahid
authors.forename: Neda
authors.initials: N
authors.lastname: Roohi
authors.forename: Farid
authors.initials: F
authors.lastname: Zayeri
mesh_terms: D000704:Analysis of Variance; D003762:Dental Instruments; D003786:Dental Pulp Cavity / Q000033:anatomy & histology* / Q000000981:diagnostic imaging / Q000601:surgery; D004867:Equipment Design; D006801:Humans; D008437:Maxilla; D008963:Molar; D009532:Nickel; D011859:Radiography; D018915:Root Canal Preparation / Q000295:instrumentation*; D018709:Statistics, Nonparametric; D014025:Titanium
chemical_list: D009532:Nickel; D014025:Titanium