title: Canal transportation after root canal instrumentation: a comparative study with computed tomography.
abstract: This in vitro study used computed tomography (CT) to compare the occurrence of canal transportation in the apical third of mesiobuccal canals in maxillary molars instrumented with 3 techniques. Sixty teeth were assigned to 3 groups (n = 20), and the root canals were instrumented as follows: Group 1, hand instrumentation with K-files; Group 2, K-files coupled to an oscillatory system powered by an electric engine; Group 3, ProTaper NiTi rotary system powered by an electric engine. To compare the canal transportation produced by the different techniques, preinstrumentation and postinstrumentation 3-dimensional CT images were obtained from root cross-sections of the region located 3 mm short of the apical foramen of each root canal. The CT scans were exported to Adobe Photoshop software, and the initial and final images were superimposed to detect the root canal wall differences between them. Canal transportation was measured by the distance between the prepared canal center and the anatomic canal center. The manual technique produced lesser canal transportation (0.10 mm) than the oscillatory and rotary techniques (0.37 and 0.22 mm, respectively); this difference was statistically significant (P=.021). All studied techniques produced canal transportation.
authors: Lutheran University of Brazil, Department of Dentistry and Endodontics, School of Dentistry, Canoas, RS, Brazil. mateushartmann@terra.com.br
authors: Mateus Silveira Martins
authors: MS
authors: Hartmann
authors: Fernando Branco
authors: FB
authors: Barletta
authors: Vânia Regina
authors: VR
authors: Camargo Fontanella
authors: José Roberto
authors: JR
authors: Vanni
mesh_terms: D003762:Dental Instruments; D003786:Dental Pulp Cavity / Q000033:anatomy & histology / Q000000981:diagnostic imaging*; D006801:Humans; D008963:Molar; D018915:Root Canal Preparation / Q000295:instrumentation / Q000379:methods*; D016369:Smear Layer; D018709:Statistics, Nonparametric; D014057:Tomography, X-Ray Computed; D014092:Tooth Root / Q000000981:diagnostic imaging