title: The correlation between fluid transport and push-out strength in root canals filled with a methacrylate-based filling material.
abstract: OBJECTIVE
  To investigate the correlation between fluid transport and dislocation resistance in canals filled with a methacrylate-based filling material.
  
  
  METHODS
  The root canals in sixty-five single-rooted human teeth were prepared to size 40, 0.06 taper. Sixty roots were filled with a single-cone technique using RealSeal SE sealer and divided into 3 groups, whilst five roots served as fluid transport positive control. Group 1 (n = 20): correlation group. Specimens were consecutively tested with fluid transport for 90 min and thereafter with the push-out test at coronal and apical root levels. Group 2 (n = 20): push-out control. Specimens were only subjected to the push-out test at coronal and apical root levels. Group 3 (n = 20): fluid transport negative control. Specimens were totally covered with nail varnish. The correlation between fluid transport and dislocation resistance was assessed by Kendall's tau-b coefficient. The Mann-Whitney U-test was used to compare dislocation resistance between groups 1 and 2 and fluid transport between groups 1 and 3. Significance level was set at P < 0.05.
  
  
  RESULTS
  Kendall's tau-b correlation coefficients between fluid transport and dislocation resistance were weak, being coronally 0.139 (P = 0.444) and apically -0.080 (P = 0.658). No significant difference in dislocation resistance could be detected between groups 1 and 2 at both root levels (P = 0.052 and P = 0.336, respectively).
  
  
  CONCLUSIONS
  No significant correlation could be identified between fluid transport and dislocation resistance, meaning that the corono-apical sealing ability of a methacrylate-based root canal filling is independent of its adhesive properties as indicated by its dislocation resistance.
authors.affiliation: Department of Endodontology, Academic Centre for Dentistry Amsterdam (ACTA), University of Amsterdam and VU University, Amsterdam, The Netherlands.
authors.forename: A-T
authors.initials: AT
authors.lastname: Moinzadeh
authors.forename: H
authors.initials: H
authors.lastname: Mirmohammadi
authors.forename: I A M
authors.initials: IA
authors.lastname: Hensbergen
authors.forename: P R
authors.initials: PR
authors.lastname: Wesselink
authors.forename: H
authors.initials: H
authors.lastname: Shemesh
mesh_terms: D003763:Dental Leakage; D003799:Dental Stress Analysis; D006801:Humans; D066298:In Vitro Techniques; D007180:Incisor; D008422:Materials Testing; D008689:Methacrylates / Q000494:pharmacology*; D011312:Pressure; D012387:Root Canal Filling Materials / Q000494:pharmacology*; D012389:Root Canal Obturation / Q000379:methods*; D018915:Root Canal Preparation / Q000379:methods*; D013499:Surface Properties
chemical_list: D008689:Methacrylates; D012387:Root Canal Filling Materials
keywords: adhesion; dislocation resistance; fluid transport; push-out; root canal filling; seal