title: Bacterial removal promoted by 2 single-file systems: Wave One and One Shape.
abstract: BACKGROUND
  Different single-file systems are available for endodontic treatment; however, comparative studies are scarce. Thus, the present study evaluated bacterial reduction promoted by 2 single-file systems: Wave One (Dentsply Maillefer, Ballaigues, Switzerland) and One Shape (Micromega, Besancon, France).
  
  
  METHODS
  Forty-five distobuccal root canals of upper molars sterilized with ethylene oxide were infected with Enterococcus faecalis for 21 days, and then root canal initial bacterial sample was collected with paper cones and plated on M-enterococcus agar. The specimens were randomly divided into 3 groups according to instrumentation (n = 15): Wave One, One Shape, and the crown-down manual technique (control group). The other 6 specimens without contamination were control asepsis. After instrumentation, samples were collected with the use of scraping and paper cones. The bacterial reduction was calculated, and then intragroup analysis was performed using the paired t test and intergroup analysis using analysis of variance (both at 5% significance).
  
  
  RESULTS
  All techniques significantly reduced the number of bacteria in the root canal (P < .05), with no significant difference between them (P > .05). The aseptic control group did not show any bacterial growth.
  
  
  CONCLUSIONS
  It can be concluded that the single-file systems Wave One and One Shape significantly reduce the bacterial number in the root canal and that there is no significant difference in their bacterial reduction abilities.
authors.affiliation: Department of Restorative Dentistry, School of Dentistry, University of São Paulo, São Paulo, SP, Brazil. Electronic address: cleberkn@hotmail.com.
authors.forename: Cleber Keiti
authors.initials: CK
authors.lastname: Nabeshima
authors.affiliation: Department of Restorative Dentistry, School of Dentistry, University of São Paulo, São Paulo, SP, Brazil.
authors.forename: Hector
authors.initials: H
authors.lastname: Caballero-Flores
authors.affiliation: Derpartment of Microbiology, Institute of Biological Science, University of São Paulo, São Paulo, SP, Brazil.
authors.forename: Silvana
authors.initials: S
authors.lastname: Cai
authors.affiliation: Department of Endodontics, School of Dentistry, Rey Juan Carlos of Madrid University, Madrid, ES-M, Spain.
authors.forename: José
authors.initials: J
authors.lastname: Aranguren
authors.affiliation: Endodontics Course, University of Cruzeiro do Sul, São Paulo, SP, Brazil.
authors.forename: Maria Leticia
authors.initials: ML
authors.lastname: Borges Britto
authors.affiliation: Department of Restorative Dentistry, School of Dentistry, University of São Paulo, São Paulo, SP, Brazil.
authors.forename: Manoel Eduardo de Lima
authors.initials: ME
authors.lastname: Machado
mesh_terms: D058491:Bacterial Load; D003786:Dental Pulp Cavity / Q000382:microbiology*; D013293:Enterococcus faecalis / Q000302:isolation & purification*; D004867:Equipment Design; D006801:Humans; D008422:Materials Testing; D008963:Molar / Q000382:microbiology; D011897:Random Allocation; D018915:Root Canal Preparation / Q000295:instrumentation*
keywords: Endodontics; Enterococcus faecalis; root canal instrumentation