title: Effect of bonded restorations on the fracture resistance of root filled teeth.
abstract: OBJECTIVE
  To evaluate the fracture resistance of root filled maxillary premolars restored with different techniques.
  
  
  METHODS
  One hundred and twenty single-rooted maxillary premolar teeth were divided randomly into six groups of 20 teeth and subjected to the following procedures: group 1: intact teeth. Group 2: endodontic access cavities prepared. Group 3: MOD cavities were prepared, root canals were filled and no restoration was placed. Group 4: teeth were prepared as group 3 and restored conventionally with amalgam. Group 5: teeth were prepared as group 3 and restored with amalgam using a bonding material. Group 6: teeth were prepared as group 3 and restored with composite resin using the same bonding material. Teeth were embedded in acrylic resin and the loads for fracture strength were applied vertically with a constant speed of 1 mm min(-1). Data were evaluated statistically with anova and Tukey's tests.
  
  
  RESULTS
  The mean force of fracture values were 1191.41, 599.86, 233.03, 494.72, 962.81 and 856.48 N for groups 1, 2, 3, 4, 5 and 6, respectively. The fracture resistance of group 5 was similar to group 1 (P > 0.05). The mean force at fracture of group 5 and group 6 was not significantly different. The fracture resistance of groups 5 and 6 was significantly higher than group 4 (P < 0.001).
  
  
  CONCLUSIONS
  The group, restored with conventional amalgam, had the weakest resistance to fracture when compared with the bonded restorations. No statistically significant differences were found between the bonded amalgam and composite resin groups.
authors.affiliation: Department of Restorative Dentistry and Endodontics, Faculty of Dentistry University of Erciyes, Kayseri, Turkey. burakasagsen@erciyes.edu.tr
authors.forename: B
authors.initials: B
authors.lastname: Sagsen
authors.forename: B
authors.initials: B
authors.lastname: Aslan
mesh_terms: D000134:Acid Etching, Dental; D001641:Bicuspid / Q000503:physiopathology; D003723:Dental Amalgam / Q000737:chemistry; D001840:Dental Bonding; D003736:Dental Cavity Lining; D003793:Dental Restoration, Permanent / Q000379:methods*; D003799:Dental Stress Analysis / Q000295:instrumentation; D006801:Humans; D008437:Maxilla; D008689:Methacrylates / Q000737:chemistry; D019279:Resin Cements / Q000737:chemistry; D012387:Root Canal Filling Materials / Q000737:chemistry / Q000627:therapeutic use; D018915:Root Canal Preparation; D012390:Root Canal Therapy; D013314:Stress, Mechanical; D013499:Surface Properties; D014082:Tooth Fractures / Q000503:physiopathology*
chemical_list: D008689:Methacrylates; D019279:Resin Cements; D012387:Root Canal Filling Materials; C084543:Super Bond D-Liner; D003723:Dental Amalgam