title: Shaping Ability of Single-file Systems with Different Movements: A Micro-computed Tomographic Study.
abstract: BACKGROUND
  This study aimed to perform a rigorous sample standardization and also evaluate the preparation of mesiobuccal (MB) root canals of maxillary molars with severe curvatures using two single-file engine-driven systems (WaveOne with reciprocating motion and OneShape with rotary movement), using micro-computed tomography (micro-CT).
  
  
  METHODS
  Ten MB roots with single canals were included, uniformly distributed into two groups (n=5). The samples were prepared with a WaveOne or OneShape files. The shaping ability and amount of canal transportation were assessed by a comparison of the pre- and post-instrumentation micro-CT scans. The Kolmogorov-Smirnov and t-tests were used for statistical analysis. The level of significance was set at 0.05.
  
  
  RESULTS
  Instrumentation of canals increased their surface area and volume. Canal transportation occurred in coronal, middle and apical thirds and no statistical difference was observed between the two systems (P>0.05). In apical third, significant differences were found between groups in canal roundness (in 3 mm level) and perimeter (in 3 and 4 mm levels) (P<0.05).
  
  
  CONCLUSIONS
  The WaveOne and One Shape single-file systems were able to shape curved root canals, producing minor changes in the canal curvature.
authors.affiliation: Department of Operative Dentistry and Endodontics, Dental College of Pernambuco, University of Pernambuco, Pernambuco, Brazil;
authors.forename: Joedy
authors.initials: J
authors.lastname: Santa-Rosa
authors.affiliation: Department of Restorative Dentistry, Faculty of Dentistry, University of São Paulo, Ribeirão Preto, Brazil.
authors.forename: Manoel Damião
authors.initials: MD
authors.lastname: de Sousa-Neto
authors.affiliation: Department of Restorative Dentistry, Faculty of Dentistry, University of São Paulo, Ribeirão Preto, Brazil.
authors.forename: Marco Aurelio
authors.initials: MA
authors.lastname: Versiani
authors.affiliation: Department of Operative Dentistry and Endodontics, Dental College of Pernambuco, University of Pernambuco, Pernambuco, Brazil;
authors.forename: Giselle
authors.initials: G
authors.lastname: Nevares
authors.affiliation: Department of Operative Dentistry and Endodontics, Dental College of Pernambuco, University of Pernambuco, Pernambuco, Brazil;
authors.forename: Felipe
authors.initials: F
authors.lastname: Xavier
authors.affiliation: Department of Operative Dentistry and Endodontics, Dental College of Pernambuco, University of Pernambuco, Pernambuco, Brazil;
authors.forename: Kaline
authors.initials: K
authors.lastname: Romeiro
authors.affiliation: Department of Operative Dentistry and Endodontics, Dental College of Pernambuco, University of Pernambuco, Pernambuco, Brazil;
authors.forename: Marcely
authors.initials: M
authors.lastname: Cassimiro
authors.affiliation: Department of Restorative Dentistry, Faculty of Dentistry, University of São Paulo, Ribeirão Preto, Brazil.
authors.forename: Graziela Bianchi
authors.initials: GB
authors.lastname: Leoni
authors.affiliation: Department of Operative Dentistry and Endodontics, Dental College of Pernambuco, University of Pernambuco, Pernambuco, Brazil;
authors.forename: Rebeca Ferraz
authors.initials: RF
authors.lastname: de Menezes
authors.affiliation: Department of Operative Dentistry and Endodontics, Dental College of Pernambuco, University of Pernambuco, Pernambuco, Brazil;
authors.forename: Diana
authors.initials: D
authors.lastname: Albuquerque
keywords: Micro-Computed Tomography; OneShape; Reciprocating Motion; Rotary System; WaveOne