title: Influence of diameter variation of Gates-Glidden drills on torsion resistance.
abstract: The aim of this study was to determine the variation of the shaft diameter close to the active cutting region and close to the radius of concordance of 28- and 32-mm Gates-Glidden drills and to analyze the diameter influence on the torsion fracture resistance. Seventy-two stainless steel Maillefer drills were studied. The drill diameter varied along the shaft, the smallest diameter occurring close to the radius of concordance. This variation causes stress concentration which leads to complete fracture of the instrument.
authors.affiliation: Associação Brasileira de Endodontia, Rio de Janeiro, Brasil.
authors.forename: H P
authors.initials: HP
authors.lastname: Lopes
authors.forename: C N
authors.initials: CN
authors.lastname: Elias
authors.forename: C
authors.initials: C
authors.lastname: Estrela
authors.forename: A
authors.initials: A
authors.lastname: Costa Filho
mesh_terms: D003762:Dental Instruments / Q000592:standards; D004867:Equipment Design; D004868:Equipment Failure; D018915:Root Canal Preparation / Q000295:instrumentation*; D012399:Rotation; D013193:Stainless Steel; D019415:Torque
chemical_list: D013193:Stainless Steel