title: Efficacy of ProTaper Universal rotary retreatment system for gutta-percha removal from root canals.
abstract: OBJECTIVE
  To evaluate the efficacy of the ProTaper Universal rotary retreatment system for gutta-percha (GP) removal from root canals.
  
  
  METHODS
  Root canals of 60 extracted human maxillary anterior teeth were prepared and filled with laterally condensed GP and AH Plus sealer. Teeth were divided into three groups: group A--GP removal completed with the ProTaper Universal rotary retreatment system and with further canal repreparation accomplished with ProTaper Universal rotary instruments; group B--GP removal was completed using Gates Glidden drills and Hedström files with chloroform as a solvent, followed with further canal repreparation with ProTaper Universal rotary instruments; group C--the same as group B for GP removal with further canal preparation with stainless steel K-flex files (Kerr). The operating time was recorded. Teeth were rendered transparent for the evaluation of the area of remaining GP/sealer in bucco-lingual and mesial-distal directions. Statistical analysis was performed by using repeated measures analysis of variance and anova. Results The ProTaper Universal technique (group A) resulted in a smaller percentage of canal area covered by residual GP/sealer than in groups B and C, with a significant difference between groups A and C (P < 0.05). Mean operating time for group A was 6.73 min, which was significantly shorter (P < 0.05) than group B (10.86 min) and group C (13.52 min).
  
  
  CONCLUSIONS
  In this laboratory study all test techniques left GP/sealer remnants within the root canal. The ProTaper Universal rotary retreatment system proved to be an efficient method of removing GP and sealer from maxillary anterior teeth.
authors: Department of Operative Dentistry and Endodontics, Guanghua College of Stomatology, Sun Yat-Sen University, Guangzhou, China.
authors: L-S
authors: LS
authors: Gu
authors: J-Q
authors: JQ
authors: Ling
authors: X
authors: X
authors: Wei
authors: X-Y
authors: XY
authors: Huang
mesh_terms: D000704:Analysis of Variance; D003481:Cuspid; D003722:Dental Alloys; D003762:Dental Instruments; D006171:Gutta-Percha; D006801:Humans; D007180:Incisor; D009532:Nickel; D019233:Retreatment / Q000295:instrumentation; D012387:Root Canal Filling Materials; D018915:Root Canal Preparation / Q000295:instrumentation*; D013193:Stainless Steel; D014025:Titanium
chemical_list: D003722:Dental Alloys; D012387:Root Canal Filling Materials; C040654:titanium nickelide; D013193:Stainless Steel; D009532:Nickel; D006171:Gutta-Percha; D014025:Titanium