title: [Research on root fracture resistance after root canal filling].
abstract: OBJECTIVE
  To compare the fracture resistance of roots filled with three different root canal filling techniques.
  
  
  METHODS
  Forty extracted single-rooted permanent teeth were instrumented and randomly divided into four groups. Three experimental groups were filled with lateral compaction technique, vertical compaction technique and single-cone technique, respectively. No filling was performed in control group. All specimens were subjected to a vertical load to cause vertical root fracture. The force required to fracture was measured and the fracture lines was classified.
  
  
  RESULTS
  Three experimental groups exhibited higher mean fracture load values than that of control group (179.93 N+/-34.03 N). There was no significant difference among the three experimental groups, and the mean fracture load values were (210.041+/-64.57), (232.55+/-50.74), (216.80+/-78.03) N, respectively. Eighty-five percent of root fracture lines were found in the bucco-lingual direction.
  
  
  CONCLUSIONS
  Root canal filling alone can't influence the root strength significantly. There is no difference in root strength after three canal filling techniques.
authors.affiliation: Dept. of Conservative Dentistry and Endodontics, West China Hospital of Stomatology, Sichuan University, Chengdu, China.
authors.forename: Lei
authors.initials: L
authors.lastname: Dou
authors.forename: Ling
authors.initials: L
authors.lastname: Ye
authors.forename: Hong
authors.initials: H
authors.lastname: Tan
authors.forename: Qiao
authors.initials: Q
authors.lastname: Chen
mesh_terms: D003786:Dental Pulp Cavity; D003799:Dental Stress Analysis; D006171:Gutta-Percha; D006801:Humans; D012387:Root Canal Filling Materials; D012389:Root Canal Obturation; D014082:Tooth Fractures; D014092:Tooth Root
chemical_list: D012387:Root Canal Filling Materials; D006171:Gutta-Percha