title: Influence of electrochemical polishing on the mechanical behaviour of nickel-titanium rotary files.
abstract: The purpose of this study was to evaluate the influence of electrochemical polishing on the cyclic fatigue, cutting efficiency and surface topography of Miltex nickel-titanium rotary files. A group of files were submitted to electrochemical polishing. New files and polished files were tested for flexural fatigue and for cutting efficiency. Scanning electron microscopy observations of all files were carried out to compare the surface morphologies of polished and new files. The t-test was used to compare the groups for cutting efficiency. Scanning electron microscopy analysis indicated that the polishing resulted in more regular surfaces in relation to the new files. Electropolished files attained a significantly higher number of cycles to fracture than new unpolished files. No statistical difference exists between the groups in relation to the cutting efficiency (t-test, P < 0.05). The polished files keep their integrity for a significantly higher number of cycles to fracture than the new files, without compromising cutting efficiency.
authors.affiliation: Department of Metallurgy and Materials, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil.
authors.forename: Marcio A C
authors.initials: MA
authors.lastname: da Silva
authors.forename: José Antônio da C
authors.initials: JA
authors.lastname: Ponciano Gomes
authors.forename: Fabiola
authors.initials: F
authors.lastname: Ormiga
mesh_terms: D019342:Acetic Acid / Q000737:chemistry; D003722:Dental Alloys / Q000737:chemistry*; D003775:Dental Polishing / Q000379:methods*; D055664:Electrochemical Techniques; D004867:Equipment Design; D004868:Equipment Failure; D006858:Hydrofluoric Acid / Q000737:chemistry; D008422:Materials Testing; D055595:Mechanical Phenomena; D008855:Microscopy, Electron, Scanning; D009532:Nickel / Q000737:chemistry*; D017942:Nitric Acid / Q000737:chemistry; D018583:Pliability; D018915:Root Canal Preparation / Q000295:instrumentation*; D012399:Rotation; D013499:Surface Properties; D014025:Titanium / Q000737:chemistry*
chemical_list: D003722:Dental Alloys; C040654:titanium nickelide; D017942:Nitric Acid; D009532:Nickel; D014025:Titanium; D019342:Acetic Acid; D006858:Hydrofluoric Acid
keywords: electrochemical polishing; endodontic instrument; fracture; nickel-titanium