title: Comparison of the cleaning efficacy of the FKG race system and hand instrument in molar root canal.
abstract: OBJECTIVE
  The aim of this study was to evaluate the ability of root canal cleaning of the RaCe rotary instrumentation system (FKG Dentaire - La-Cheaux-de Fonds - Switzerland), compared to manual filing with Stainless Steel K-files (Maillefer Instruments - Ballaigues - Switzerland).
  
  
  METHODS
  Twenty extracted human teeth (maxillary molars) were selected and their pulp tissue was removed after coronal access. The root canals were filled with a dye (India ink) and allowed to dry for 48 hours, followed by establishment of the working length of the mesiobuccal root; then, half of the specimens were instrumented by the modified Oregon technique and the other half were instrumented by crown-down sequence of the RaCe system. After preparation, the teeth were longitudinally sectioned and evaluated according to the amount of remaining dye.
  
  
  RESULTS
  Data obtained were registered as numerical scores, and the arithmetic means were compared between groups using the Mann Whitney test. Both techniques were unable to completely clean the interior of the root canals, with a better performance of the manual technique only at the middle third.
  
  
  CONCLUSIONS
  It could be concluded that the RaCe system was able to provide satisfactory cleaning, similar to that obtained by the manual instrumentation technique.
authors.affiliation: Hospital de Reabilitação de Anomalias Craniofaciais - USP, Bauru, SP, Brazil. sipert@usp.br
authors.forename: Carla Renata
authors.initials: CR
authors.lastname: Sipert
authors.forename: Renata Pardini
authors.initials: RP
authors.lastname: Hussne
authors.forename: Celso Kenji
authors.initials: CK
authors.lastname: Nishiyama