title: A 1-year follow-up study on leakage of single-cone fillings with RoekoRSA sealer.
abstract: OBJECTIVE
  The aim of this study was to measure long-term leakage along single cone (SC) fillings.
  
  
  METHODS
  Two groups of canines (n = 30) were prepared and a size 55 file was the apical master file. Step-back was performed using files of sizes 60, 70, and 80. The canals were filled by the single cone technique using RoekoRSA as sealer. To place sealer into each canal, a bidirectional spiral was used in 1 group, whereas a gutta-percha cone was used in the other group. Immediately after root filling, the coronal portion of root filling was removed by postspace preparation. Leakage along the 4 mm remaining apical root filling was measured after 1 week and again after 1 year using a fluid transport model. Ten additional canine roots were prepared and filled with gutta-percha cones without sealer, serving as positive controls. Occurrence of apical extrusion of materials was recorded.
  
  
  RESULTS
  The apical root filling in all 60 canine roots did not show leakage either at 1 week or at 1 year. All 10 positive controls showed gross leakage (>20 muL/h). In no case gutta-percha extruded through the apical foramen. Sealer extruded apically in 88% of the roots where a gutta-percha cone was used to introduce sealer, whereas in 28% of the roots where a bidirectional spiral was used to introduce sealer (by chi-square test, P < .05).
  
  
  CONCLUSIONS
  In wide and straight canals, SC fillings with RoekoRSA sealer prevented fluid transport for 1 year. Using bidirectional spiral to place sealer reduced sealer extrusion under the conditions of this experiment.
authors.affiliation: Department of Cariology Endodontology Pedodontology, Academic Centre for Dentistry Amsterdam (ACTA), Amsterdam, The Netherlands. m.wu@acta.nl
authors.forename: Min-Kai
authors.initials: MK
authors.lastname: Wu
authors.forename: Luc W M
authors.initials: LW
authors.lastname: van der Sluis
authors.forename: Paul R
authors.initials: PR
authors.lastname: Wesselink
mesh_terms: D003481:Cuspid; D003738:Dental Cements; D003763:Dental Leakage / Q000517:prevention & control*; D005119:Extravasation of Diagnostic and Therapeutic Materials; D005500:Follow-Up Studies; D006801:Humans; D012387:Root Canal Filling Materials; D012389:Root Canal Obturation / Q000379:methods*; D019227:Tooth Apex
chemical_list: D003738:Dental Cements; D012387:Root Canal Filling Materials; C465381:roeko seal