title: Effect of intra-orifice barriers on the fracture resistance of endodontically treated teeth - an ex-vivo study.
abstract: BACKGROUND
  The purpose of this study was to evaluate and compare the fracture resistance of roots obturated with guttapercha using bonded amalgam, GC Light cure GIC (resin modified glass ionomer cement) and Tetric N Flow (flowable hybrid composite) as different intra orifice barriers.
  
  
  METHODS
  Eighty freshly extracted mandibular premolars with straight roots were reduced to 14 mm from the coronal aspect. All canals were enlarged to size 30 and specimens were obturated with gutta percha cones, except for control group specimens the coronal 3 mm of root fillings of all other group specimens were removed with the aid of heated plugger. All samples were randomly divided into 4 groups of 20 specimens each. They were control, Fuji GC LC GIC, Tetric N Flow and Bonded Amalgam. After the placement of the intra orifice barrier materials, specimens stored at 37(o)C and 100% humidity for one week to allow the materials to set completely. After one week, all the groups were subjected to fracture resistance testing by using Universal testing machine.
  
  
  RESULTS
  Data was analysed for significance by ANOVA (Analysis of variance) and further pair wise comparison was performed by Benferroni test. Level of significance was taken as 0.05. Tetric N Flow group showed better fracture resistance as compared to all other groups and Control group is least among the groups. Fracture resistance of Tetric N Flow compared with bonded amalgam was statistically significant.
  
  
  CONCLUSIONS
  Tetric N Flow and Fuji GC LC GIC can be used as intra-orifice barriers with good fracture resistance in endodontically treated teeth.
authors: Senior Lecturer, Department of Conservative Dentistry & Endodontics, Malabar Dental College and Research Centre , Edappal, Kerala, India .
authors: Shaheen
authors: S
authors: Aboobaker
authors: Professor and Head of The Department, Department of Conservative Dentistry & Endodontics, Malabar Dental College and Research Centre , Edappal, Kerala, India .
authors: Baiju Gopalan
authors: BG
authors: Nair
authors: Professor, Department of Conservative Dentistry & Endodontics, Noorul Islam College of Dental Sciences , Neyyatinkara, Kerala, India .
authors: Rajesh
authors: R
authors: Gopal
authors: Senior Lecturer, Department of Conservative Dentistry & Endodontics, Malabar Dental College and Research Centre , Edappal, Kerala, India .
authors: Sandeep
authors: S
authors: Jituri
authors: Senior Lecturer, Department of Conservative Dentistry & Endodontics, Malabar Dental College And Research Centre , Edappal, Kerala, India .
authors: Fazalu Rahman Pothu
authors: FR
authors: Veetil
keywords: Bonded amalgam; Flowable composite; Glass ionomer cement; Intra-orifice barriers; LC GIC (light cure glass ionomer cement)