title: Surface characterization of nickel titanium orthodontic arch wires.
abstract: BACKGROUND
  Surface roughness of nickel titanium orthodontic arch wires poses several clinical challenges. Surface modification with aesthetic/metallic/non metallic materials is therefore a recent innovation, with clinical efficacy yet to be comprehensively evaluated.
  
  
  METHODS
  One conventional and five types of surface modified nickel titanium arch wires were surface characterized with scanning electron microscopy, energy dispersive analysis, Raman spectroscopy, Atomic force microscopy and 3D profilometry. Root mean square roughness values were analyzed by one way analysis of variance and post hoc Duncan's multiple range tests.
  
  
  RESULTS
  Study groups demonstrated considerable reduction in roughness values from conventional in a material specific pattern: Group I; conventional (578.56 nm) > Group V; Teflon (365.33 nm) > Group III; nitride (301.51 nm) > Group VI (i); rhodium (290.64 nm) > Group VI (ii); silver (252.22 nm) > Group IV; titanium (229.51 nm) > Group II; resin (158.60 nm). It also showed the defects with aesthetic (resin/Teflon) and nitride surfaces and smooth topography achieved with metals; titanium/silver/rhodium.
  
  
  CONCLUSIONS
  Resin, Teflon, titanium, silver, rhodium and nitrides were effective in decreasing surface roughness of nickel titanium arch wires albeit; certain flaws. Findings have clinical implications, considering their potential in lessening biofilm adhesion, reducing friction, improving corrosion resistance and preventing nickel leach and allergic reactions.
authors: Classified Specialist (Orthodontics), Dept of Dental Research & Implantology, Institute of Nuclear Medicine and Allied Sciences (INMAS), Defence Research and Development Organization (DRDO), Timarpur, Delhi 1100054, India.
authors: Manu
authors: M
authors: Krishnan
authors: Research Scholar, School of Medicine and Paramedical Health Sciences, Guru Gobind Singh Indraprastha University, Delhi Cantt, India.
authors: Saraswathy
authors: S
authors: Seema
authors: Senior Research Fellow (Project), Dept of Dental Research & Implantology, Institute of Nuclear Medicine and Allied Sciences (INMAS), Defence Research and Development Organization (DRDO), Timarpur, Delhi, India.
authors: Brijesh
authors: B
authors: Tiwari
authors: Commanding Officer, Military Dental Centre, Delhi Cantt, India.
authors: Himanshu S
authors: HS
authors: Sharma
authors: Addl Director General Dental Services, IHQ of MoD (Army), New Delhi 110001, India.
authors: Sanjay
authors: S
authors: Londhe
authors: Director General Dental Services & Colonel Commandant, O/o DGDS, Adjutant General's Branch, IHQ of MoD, L Block, New Delhi 110001, India.
authors: Vimal
authors: V
authors: Arora
keywords: 3D profilometry; Atomic force microscopy; Nickel titanium arch wire; Raman spectroscopy; Root mean square roughness; Scanning electron microscopy