title: [Analysis of vertical root fracture with two different techniques of root canal preparation].
abstract: OBJECTIVE
  To investigate the relationship of vertical root fracture (VRF) after root canal treatment with two different technique of root canal shaping and provide clinical reference.
  
  
  METHODS
  1702 teeth treated with root canal treatment during recent 2 years. All teeth were divided into two groups according to different techniques of root canal shaping: 643 teeth were prepared with NiTi rotary preparation technique (NRPT) and 1059 teeth were prepared with stainless steel hand K-files preparation technique(SSPT). The clinical symptoms and signs, radiological findings were estimated. The data was analyzed by SPSS 11.5 software package.
  
  
  RESULTS
  There were 32 teeth with vertical root fracture, the VRF rate was 1.88%. The VRF rate in NRPT group was significantly higher than in SSPT group (P<0.01). The VRF rate with retreatment history in NRPT group was significantly higher than in SSPT group (P<0.01), but The VRF rate with post and core restoration in both NRPT and SSPT groups was not significantly different(P>0.05).
  
  
  CONCLUSIONS
  NiTi rotary preparation technique (NRPT) was closely related with vertical root fracture (VRF). And the VRF risk would be even higher if the tooth underwent root canal retreatment case or a post-core was placed in the root canal.
authors.affiliation: DDS Dental Care in Shanghai, China. info@dds-dental.com
authors.forename: Xiao-jie
authors.initials: XJ
authors.lastname: Gao
authors.forename: Wei-ning
authors.initials: WN
authors.lastname: Xu
mesh_terms: D006801:Humans; D018915:Root Canal Preparation; D012390:Root Canal Therapy; D013193:Stainless Steel; D014092:Tooth Root
chemical_list: D013193:Stainless Steel