title: Permeability and smear layer removal: effects of different chemical agents on the primary root dentin.
abstract: OBJECTIVE
  The purpose of this study was to evaluate the effects of chemical agents on the permeability and removal of the smear layer in the primary root dentin.
  
  
  METHODS
  Fifty roots were distributed into 6 groups: (1) 5.25% sodium hypochlorite (SH); (2) 5.25% SH+17% ethylenedia-minetetraacetic acid (SHE); (3) 2% chlorhexidine (CHX); (4) 2% CHX+17% ethylenediaminetetraacetic acid (CHXE); (5) 17% EDTA (E); and (6) saline solution (SS). The canals were instrumented and irrigated. The roots were dyed, washed, and sectioned, and the permeability index was measured. The amount of smear layer was scored. Data were submitted to analysis of variance, Kruskal-Wallis, Student-Newman-Keuls and t tests (P<.05).
  
  
  RESULTS
  Significant differences were observed in the cervical and apical thirds for the CHX (P=.03), CHXE (P=.027), SS (P=.038), and SH (P<.001) groups. The SS group showed a heavy smear layer in all thirds. Root canals treated with SHE showed great cleaning in the cervical, middle, and apical thirds.
  
  
  CONCLUSIONS
  Sodium hypochlorite associated with ethylenediaminetetraacetic acid produces the best root canal cleaning and the highest permeability in all thirds.
authors.affiliation: Pediatric Dentistry Department, Piracicaba Dental School, University of Campinas, Piracicaba, São Paulo, Brazil. fmpascon@fop.unicamp.br
authors.forename: Fernanda Miori
authors.initials: FM
authors.lastname: Pascon
authors.forename: Kamila Rosamilia
authors.initials: KR
authors.lastname: Kantovitz
authors.forename: Fabiana Dubau
authors.initials: FD
authors.lastname: Cavallaro
authors.forename: Regina Maria
authors.initials: RM
authors.lastname: Puppin-Rontani
mesh_terms: D003804:Dentin / Q000187:drug effects*; D006801:Humans; D008855:Microscopy, Electron, Scanning; D010539:Permeability; D014092:Tooth Root / Q000187:drug effects*