title: Sealer penetration into dentinal tubules in the presence or absence of smear layer: a confocal laser scanning microscopic study.
abstract: BACKGROUND
  The aim of this study was to test the dentinal tubule penetration of AH26 (Dentsply DeTrey, Konstanz, Germany) and MTA Fillapex (Angelus, Londrina, PR, Brazil) in instrumented root canals obturated by using cold lateral compaction or warm vertical compaction techniques in either the presence or absence of the smear layer.
  
  
  METHODS
  Forty-five extracted single-rooted human mandibular premolar teeth were used. The crowns were removed, and the root canals were instrumented by using the Self-Adjusting File (ReDent-Nova, Ra'anana, Israel) with continuous sodium hypochlorite (2.6%) irrigation. Final irrigation was either with 5% EDTA or with sodium hypochlorite. The canals were dried and obturated by using rhodamine B-labeled AH26 or MTA Fillapex in combination with the cold lateral compaction or the warm vertical compaction technique. After setting, the roots were sectioned horizontally at 4-, 8-, and 12-mm distances from the apical tip. On each section, sealer penetration in the dentinal tubules was measured by using confocal laser scanning microscopy.
  
  
  RESULTS
  Regardless of the usage of EDTA, MTA Fillapex, compared with AH26, was associated with greater sealer penetration when used with the cold lateral compaction technique, and, conversely, AH26, compared with MTA Fillapex, was associated with greater sealer penetration when used with the warm vertical compaction technique (P < .05). Removal of the smear layer increased the penetration depth of MTA Fillapex used with the cold lateral compaction technique (P < .05); however, it had no significant effect on the penetration depth of AH26.
  
  
  CONCLUSIONS
  Greater sealer penetration could be achieved with either the MTA Fillapex-cold lateral compaction combination or with the AH26-warm vertical compaction combination. Smear layer removal was critical for the penetration of MTA Fillapex; however, the same did not hold for AH26.
authors.affiliation: Department of Dental Pathology and Endodontics, University Dentistry Clinical Center of Kosovo, University of Prishtina, Prishtina, Kosovo.
authors.forename: Astrit
authors.initials: A
authors.lastname: Kuçi
authors.affiliation: Department of Endodontics, Faculty of Dentistry, Gazi University, Ankara, Turkey.
authors.forename: Tayfun
authors.initials: T
authors.lastname: Alaçam
authors.affiliation: Department of Endodontics, Faculty of Dentistry, Gazi University, Ankara, Turkey.
authors.forename: Ozer
authors.initials: O
authors.lastname: Yavaş
authors.affiliation: Department of Biology, Faculty of Science, Ankara University, Ankara, Turkey.
authors.forename: Zeynep
authors.initials: Z
authors.lastname: Ergul-Ulger
authors.affiliation: Department of Endodontics, Faculty of Dentistry, Gazi University, Ankara, Turkey. Electronic address: guvenk@gazi.edu.tr.
authors.forename: Guven
authors.initials: G
authors.lastname: Kayaoglu
mesh_terms: D017607:Aluminum Compounds / Q000737:chemistry*; D017610:Calcium Compounds / Q000737:chemistry*; D003786:Dental Pulp Cavity / Q000648:ultrastructure; D003804:Dentin / Q000648:ultrastructure*; D004338:Drug Combinations; D004492:Edetic Acid / Q000627:therapeutic use; D004853:Epoxy Resins / Q000737:chemistry*; D005456:Fluorescent Dyes; D006801:Humans; D008422:Materials Testing; D018613:Microscopy, Confocal / Q000379:methods; D008855:Microscopy, Electron, Scanning; D010087:Oxides / Q000737:chemistry*; D011897:Random Allocation; D012235:Rhodamines; D012387:Root Canal Filling Materials / Q000737:chemistry*; D012388:Root Canal Irrigants / Q000627:therapeutic use; D012389:Root Canal Obturation / Q000379:methods; D018915:Root Canal Preparation / Q000295:instrumentation; D017640:Silicates / Q000737:chemistry*; D016369:Smear Layer / Q000473:pathology*; D012973:Sodium Hypochlorite / Q000627:therapeutic use; D013696:Temperature; D019227:Tooth Apex / Q000648:ultrastructure
chemical_list: D017607:Aluminum Compounds; D017610:Calcium Compounds; D004338:Drug Combinations; D004853:Epoxy Resins; D005456:Fluorescent Dyes; D010087:Oxides; D012235:Rhodamines; D012387:Root Canal Filling Materials; D012388:Root Canal Irrigants; D017640:Silicates; C534916:epoxy resin-based root canal sealer; C086631:mineral trioxide aggregate; D004492:Edetic Acid; D012973:Sodium Hypochlorite; C029773:rhodamine B
keywords: Butterfly effect; epoxy resin; lateral condensation; mineral trioxide aggregate; thermoplastic; warm gutta-percha