title: [The influence of smear layer and different sealers on apical microleakage of root canals obturated with Ultrafil-3D system].
abstract: OBJECTIVE
  To evaluate the sealing properties of Ultrafil-3D system with three different root canal sealers in absence or presence of smear layer.
  
  
  METHODS
  64 straight single-root anterior teeth were selected and root canals were instrumented. 60 teeth were divided into two groups with or without smear layer. Each group was then divided into three subgroups, three different sealers (AH-plus, Roekoseal, CRCS) were applied in each subgroup when the root canals were obturated with Ultrafil-3D system (using Firm set gutta-percha). Other 4 teeth were used as control. After dyed in 2% methyl blue for 5 days, all teeth were longitudinally split from mesiodistal surface into two parts. The linear length of dye was measured for apical microleakage. SAS6.04 software was used for statistical analysis.
  
  
  RESULTS
  (1) The linear dye penetration was significantly higher in group A (CRCS) compared with that in group B (AH-plus) and in group C (Roekoseal) (P<0.05). (2) Whether the smear layer was absent or present, the apical microleakage had no significant difference when using gutta-percha of Ultrafil-3D system with the same sealer (P>0.05).
  
  
  CONCLUSIONS
  Root-canal obturation with Ultrafil-3D gutta-percha can obtain better sealing ability when AH-plus or Roekoseal is applied as sealer. Removing the smear layer can not significantly reduce the apical microleakage.
authors.affiliation: Department of Endodontics, School of Stomatology, Ninth People's Hospital, Shanghai Jiao Tong University, China.
authors.forename: Rong
authors.initials: R
authors.lastname: Du
authors.forename: Ya-qin
authors.initials: YQ
authors.lastname: Zhu
mesh_terms: D003763:Dental Leakage; D006171:Gutta-Percha / Q000737:chemistry*; D006801:Humans; D012387:Root Canal Filling Materials / Q000737:chemistry*; D012389:Root Canal Obturation; D016369:Smear Layer
chemical_list: D012387:Root Canal Filling Materials; D006171:Gutta-Percha