title: Micro-Computed Tomographic Evaluation of Hard Tissue Debris Removal after Different Irrigation Methods and Its Influence on the Filling of Curved Canals.
abstract: BACKGROUND
  The aim of this study was to compare the efficacy of passive ultrasonic irrigation (PUI) and the EndoVac (EV) System (Discus Dental, Culver City, CA) in hard tissue debris removal and its influence on the quality of the root canal filling with the aid of micro-computed tomographic scanner.
  
  
  METHODS
  Twenty-four mandibular molars were subjected to 4 microtomographic scannings (ie, before and after instrumentation, after final irrigation, and after obturation) using the SkyScan 1176 X-ray microtomograph (Bruker microCT, Kontich, Belgium) at a resolution of 17.42 μm. Mesial canals were prepared using R25 Reciproc instruments (VDW GmbH, Munich, Germany) and divided into 2 groups according to the final irrigation method: the PUI group (n = 12) and the EV group (n = 12). All specimens were filled with the continuous wave of condensation technique. CTAn and CTvol software (Bruker microCT) were used for volumetric analysis and 3-dimensional model reconstruction of the root canals, hard tissue debris, and the filling material. Data were statistically analyzed using the Student t test.
  
  
  RESULTS
  Analysis of the micro-computed tomographic scans revealed debris accumulated inside the root canals, occupying an average of 3.4% of the canal's volume. Irrigation with PUI and the EV system reduced the volume of hard tissue debris in 55.55% and 53.65%, respectively, with no statistical difference between them (P > .05). Also, there was no difference among the groups with regard to the volume of filling material and voids (P > .05).
  
  
  CONCLUSIONS
  PUI and the EV system were equally efficient in the removal of hard tissue debris and the quality of root canal filling was similar in both groups, with no influence from the irrigation method.
authors.affiliation: Division of Endodontics, Department of Restorative Dentistry, School of Dentistry, University of São Paulo, São Paulo, São Paulo, Brazil.
authors.forename: Laila Gonzales
authors.initials: LG
authors.lastname: Freire
authors.affiliation: Division of Endodontics, Department of Restorative Dentistry, School of Dentistry, University of São Paulo, São Paulo, São Paulo, Brazil.
authors.forename: Elaine Faga
authors.initials: EF
authors.lastname: Iglecias
authors.affiliation: Endodontology, Restorative Dentistry, College of Dentistry, University of Manitoba, Winnipeg, Canada.
authors.forename: Rodrigo Sanches
authors.initials: RS
authors.lastname: Cunha
authors.affiliation: Division of Endodontics, Restorative Dentistry, School of Dentistry, University of São Paulo, São Paulo, São Paulo, Brazil.
authors.forename: Marcelo
authors.initials: M
authors.lastname: Dos Santos
authors.affiliation: Division of Endodontics, Restorative Dentistry, School of Dentistry, University of São Paulo, São Paulo, São Paulo, Brazil. Electronic address: ggavini@usp.br.
authors.forename: Giulio
authors.initials: G
authors.lastname: Gavini
mesh_terms: D003786:Dental Pulp Cavity / Q000000981:diagnostic imaging*; D006801:Humans; D008334:Mandible; D008963:Molar / Q000000981:diagnostic imaging; D012388:Root Canal Irrigants / Q000008:administration & dosage*; D018915:Root Canal Preparation / Q000379:methods*; D016369:Smear Layer; D007507:Therapeutic Irrigation / Q000379:methods*; D014465:Ultrasonics; D055114:X-Ray Microtomography
chemical_list: D012388:Root Canal Irrigants
keywords: Debris; irrigation; micro–computed tomography; root canal filling