title: Does a final rinse to remove smear layer interfere on dentin permeability of root canals?
abstract: OBJECTIVE
  The objective of this study was to assess the influence of different final irrigating solutions on dentin permeability and smear layer removal using the same specimens and relate the results obtained.
  
  
  METHODS
  Forty anterior human teeth were instrumented and divided into 4 groups (n = 10) at the final rinse step, according to the irrigant used: G I (control) - 1% NaOCl; G II - 17% EDTA; G III - 17% EDTAT; and G IV - Biopure MTAD. The canals were filled with 0.5% methylene blue and maintained in bottles for 48 hours. The roots were transversally split in coronal, middle, and apical fragments. The specimens were photographed and analyzed regarding dye penetration. The fragments were then axially split and prepared for SEM. The photomicrographs were analyzed and qualified by scores.
  
  
  RESULTS
  Only the EDTA-T group exhibited statistical difference in which the apical third had less dentin permeability (P < .05). When a decalcifying agent was used, smear layer was removed, which did not happen in the NaOCl group. Regarding smear layer removal, differences were found only in the EDTA group in which the apical third presented more smear layer (P < .05). No correlation was found for both studies (r = 0.4207).
  
  
  CONCLUSIONS
  There was not an even relationship between the results from both studies, which inferes that higher or lower dentinal permeability does not necessarily correspond to a higher or lower amount of smear layer. The analysis of dentin permeability and smear layer removal was shown to be a feasible procedure using the same specimens.
authors.affiliation: Faculty of Dentistry, University of Manitoba, Winnipeg, Manitoba, Canada. imello2@hotmail.com
authors.forename: Isabel
authors.initials: I
authors.lastname: Mello
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Coil
authors.forename: João Humberto
authors.initials: JH
authors.lastname: Antoniazzi
mesh_terms: D019343:Citric Acid / Q000494:pharmacology; D003786:Dental Pulp Cavity / Q000187:drug effects*; D003806:Dentin Permeability / Q000187:drug effects*; D004318:Doxycycline / Q000494:pharmacology; D004492:Edetic Acid / Q000494:pharmacology; D006801:Humans; D007180:Incisor; D011136:Polysorbates / Q000494:pharmacology; D012388:Root Canal Irrigants / Q000494:pharmacology*; D016369:Smear Layer; D012973:Sodium Hypochlorite / Q000494:pharmacology
chemical_list: C475043:MTAD (intracanal irrigant); D011136:Polysorbates; D012388:Root Canal Irrigants; D019343:Citric Acid; D004492:Edetic Acid; D012973:Sodium Hypochlorite; D004318:Doxycycline