title: A comparison of three Ni-Ti rotary instruments in apical transportation.
abstract: The purpose of this study was to compare apical transportation and changes in canal curvature of three nickel-titanium (Ni-Ti) rotary instruments: Hero 642, RaCe, and ProTaper. Mesiobuccal canals of 60 maxillary first molars (with angles of curvature between 25 degrees and 35 degrees) were prepared with a torque-control, low-speed engine. Canals were prepared using the crown-down technique to the size of #30. Using a radiographic platform, reproducible preinstrumentation and postinstrumentation radiographs were taken. A computer analysis allowed magnification and superimposition of the images. The central axes of initial and final instruments were radiographically superimposed to measure transportation at 1 mm from WL. Data were analyzed using repeated-measures ANOVA. A statistically significant difference in apical transportation was found in ProTaper group. The results suggest that ProTaper file system be implemented in combination with other less tapered more flexible systems, like RaCe, in preparing curved canals.
authors.affiliation: Department of Endodontics, Dental Research Center, Shaheed Beheshti University, Evin, Tehran Iran. hoom999@yahoo.com
authors.forename: Homan Hossein
authors.initials: HH
authors.lastname: Javaheri
authors.forename: Ghasem Hossein
authors.initials: GH
authors.lastname: Javaheri
mesh_terms: D003722:Dental Alloys; D003762:Dental Instruments; D003786:Dental Pulp Cavity / Q000033:anatomy & histology; D003799:Dental Stress Analysis; D003804:Dentin; D004867:Equipment Design; D006801:Humans; D008963:Molar; D009532:Nickel; D018915:Root Canal Preparation / Q000295:instrumentation*; D016369:Smear Layer; D014025:Titanium; D019227:Tooth Apex / Q000033:anatomy & histology
chemical_list: D003722:Dental Alloys; C040654:titanium nickelide; D009532:Nickel; D014025:Titanium