title: Comparison of galvanic corrosion potential of metal injection molded brackets to that of conventional metal brackets with nickel-titanium and copper nickel-titanium archwire combinations.
abstract: OBJECTIVE
  The aim of the study is to investigate the galvanic corrosion potential of metal injection molding (MIM) brackets to that of conventional brackets under similar in vitro conditions with nickel-titanium and copper nickel-titanium archwires.
  
  
  METHODS
  Twenty-five maxillary premolar MIM stainless steel brackets and 25 conventional stainless steel brackets and archwires, 0.16 inch, each 10 mm length, 25 nickeltitanium wires, 25 copper nickel-titanium wires were used. They were divided into four groups which had five samples each. Combination of MIM bracket with copper nickel-titanium wire, MIM bracket with nickel-titanium wire and conventional stainless steel brackets with copper nickel-titanium wire and conventional stainless steel brackets with nickel-titanium wires which later were suspended in 350 ml of 1 M lactic acid solution media. Galvanic corrosion potential of four groups were analyzed under similar in vitro conditions. Precorrosion and postcorrosion elemental composition of MIM and conventional stainless steel bracket by scanning electron microscope (SEM) with energy dispersive spectroscope (EDS) was done.
  
  
  RESULTS
  MIM bracket showed decreased corrosion susceptibility than conventional bracket with copper nickeltitanium wire. Both MIM and conventional bracket showed similar corrosion resistance potential in association with nickel-titanium archwires. It seems that both brackets are more compatible with copper nickel-titanium archwires regarding the decrease in the consequences of galvanic reaction. The EDS analysis showed that the MIM brackets with copper nickel-titanium wires released less metal ions than conventional bracket with copper nickeltitanium wires.
  
  
  CONCLUSIONS
  MIM brackets showed decreased corrosion susceptibility, copper nickel-titanium archwires are compatible with both the brackets than nickel-titanium archwires.
  
  
  CONCLUSIONS
  Clinically MIM and conventional brackets behaved more or less similarly in terms of corrosion resistance. In order to decrease the corrosion potential of MIM brackets, more precise manufacturing technique should be improved to get a more smoother surface finish.
authors.affiliation: Professor, Department of Orthodontics, Vishnu Dental College Bhimavaram-534202, Andhra Pradesh, India, e-mail: dpkvarma@yahoo.com.
authors.forename: D Praveen Kumar
authors.initials: DP
authors.lastname: Varma
authors.forename: S
authors.initials: S
authors.lastname: Chidambaram
authors.forename: K Baburam
authors.initials: KB
authors.lastname: Reddy
authors.forename: M
authors.initials: M
authors.lastname: Vijay
authors.forename: D
authors.initials: D
authors.lastname: Ravindranath
authors.forename: M Rajendra
authors.initials: MR
authors.lastname: Prasad
mesh_terms: D003300:Copper / Q000737:chemistry*; D003343:Corrosion; D003722:Dental Alloys / Q000737:chemistry*; D004563:Electrochemistry; D006801:Humans; D006863:Hydrogen-Ion Concentration; D019344:Lactic Acid / Q000737:chemistry; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D009532:Nickel / Q000737:chemistry*; D016382:Orthodontic Appliance Design; D016910:Orthodontic Brackets; D009969:Orthodontic Wires; D013052:Spectrometry, X-Ray Emission; D013193:Stainless Steel / Q000737:chemistry*; D013499:Surface Properties; D014025:Titanium / Q000737:chemistry*
chemical_list: C415948:Copper NiTi; D003722:Dental Alloys; C040654:titanium nickelide; D013193:Stainless Steel; D019344:Lactic Acid; D003300:Copper; D009532:Nickel; D014025:Titanium