title: Effect of different intraorifice barriers on the fracture resistance of roots obturated with Resilon or gutta-percha.
abstract: BACKGROUND
  This study investigated and compared the root reinforcement potential of 3 different intraorifice barriers (mineral trioxide aggregate [MTA], resin-modified glass ionomer cement [Vitremer], and fiber-reinforced composite [FRC]) placed over root canals obturated with gutta-percha or Resilon.
  
  
  METHODS
  Crowns of 80 extracted human mandibular premolars were sectioned off to obtain 14-mm-long root specimens. After preparation of root canals with nickel-titanium rotary files, the roots were obturated with either the Resilon/Epiphany system or gutta-percha + AH Plus sealer. In both obturation groups, specimens were further subgrouped with respect to the intraorifice barrier material placed after removal of 3-mm coronal portion of the root fillings: (1) MTA, (2) Vitremer, and (3) FRC. The specimens were loaded vertically at 1 mm/min crosshead speed until vertical root fracture occurred. Results were evaluated statistically with two-way analysis of variance and Tukey tests.
  
  
  RESULTS
  Fracture resistance of roots was significantly affected by the type of intraorifice barrier (P < .05), but not by the type of obturation system used (P > .05).
  
  
  CONCLUSIONS
  The use of Vitremer and FRC significantly improved the fracture resistance, whereas MTA did not exhibit any reinforcing effect as an intraorifice barrier.
authors.affiliation: Department of Endodontics, Faculty of Dentistry, Hacettepe University, Ankara, Turkey. emrenagas@yahoo.com
authors.forename: Emre
authors.initials: E
authors.lastname: Nagas
authors.forename: Ozgur
authors.initials: O
authors.lastname: Uyanik
authors.forename: Emre
authors.initials: E
authors.lastname: Altundasar
authors.forename: Veli
authors.initials: V
authors.lastname: Durmaz
authors.forename: Zafer C
authors.initials: ZC
authors.lastname: Cehreli
authors.forename: Pekka K
authors.initials: PK
authors.lastname: Vallittu
authors.forename: Lippo V J
authors.initials: LV
authors.lastname: Lassila
mesh_terms: D017607:Aluminum Compounds / Q000737:chemistry / Q000627:therapeutic use; D001641:Bicuspid / Q000473:pathology; D017610:Calcium Compounds / Q000737:chemistry / Q000627:therapeutic use; D003188:Composite Resins / Q000737:chemistry / Q000627:therapeutic use; D003786:Dental Pulp Cavity / Q000187:drug effects*; D003799:Dental Stress Analysis / Q000295:instrumentation; D004338:Drug Combinations; D004853:Epoxy Resins / Q000737:chemistry / Q000627:therapeutic use; D005899:Glass Ionomer Cements / Q000737:chemistry / Q000627:therapeutic use; D006171:Gutta-Percha / Q000737:chemistry / Q000627:therapeutic use*; D006801:Humans; D008422:Materials Testing; D010087:Oxides / Q000737:chemistry / Q000627:therapeutic use; D019279:Resin Cements / Q000737:chemistry / Q000627:therapeutic use; D012387:Root Canal Filling Materials / Q000737:chemistry / Q000627:therapeutic use*; D018915:Root Canal Preparation / Q000295:instrumentation / Q000379:methods; D017640:Silicates / Q000737:chemistry / Q000627:therapeutic use; D013314:Stress, Mechanical; D014082:Tooth Fractures / Q000517:prevention & control*; D014092:Tooth Root / Q000293:injuries*
chemical_list: D017607:Aluminum Compounds; D017610:Calcium Compounds; D003188:Composite Resins; D004338:Drug Combinations; D004853:Epoxy Resins; D005899:Glass Ionomer Cements; D010087:Oxides; C438843:Panavia-Fluoro; D019279:Resin Cements; D012387:Root Canal Filling Materials; D017640:Silicates; C084550:Vitremer; C486893:epiphany sealer; C534916:epoxy resin-based root canal sealer; C496140:everStick; C086631:mineral trioxide aggregate; C486892:resilon sealer; D006171:Gutta-Percha