title: Mechanical properties and surface characterization of translucent composite wire following topical fluoride treatment.
abstract: OBJECTIVE
  To determine the effects of a fluoride prophylactic agent on the mechanical properties and surface quality of a preformed round translucent composite archwire while comparing it with nickel-titanium (Ni-Ti) and multistranded stainless steel wires.
  
  
  METHODS
  The wires were immersed in an acidulated phosphate fluoride solution (APF) or in distilled water (control) for 1.5 hours at 37°C. Flexural modulus of elasticity (E) and yield strength (YS) of the wires were measured using a three-point bending test in a universal testing machine. The springback ratio (YS/E) was calculated for each wire. The influence of fluoride treatment on properties of the wires was statistically analyzed using Student's t-test at α  =  .05. Surface changes were observed with a scanning electron microscope.
  
  
  RESULTS
  Fluoride treatment produced a statistically significant reduction in E, YS, and YS/E of the composite wire (P < .05). In addition, a significant decrease in E of Ni-Ti wire was found after exposure to fluoride, upon comparison with distilled water control treatment. On the other hand, no significant effect of fluoride treatment was found on YS and YS/E of Ni-Ti wire and on studied properties of the multistranded stainless steel wire (P > .05). Corrosive changes in surface topography were observed after exposure to the fluoride agent and were more pronounced with the composite wire.
  
  
  CONCLUSIONS
  These results suggest that using a topical fluoride agent with translucent composite wire could decrease the mechanical properties and might damage the surface of the wire, potentially contributing to prolonged orthodontic treatment.
authors: Department of Orthodontics, Faculty of Dentistry, Mansoura University, Mansoura, Egypt. shazamohammad@yahoo.com
authors: Shaza M
authors: SM
authors: Hammad
authors: Essam E
authors: EE
authors: Al-Wakeel
authors: El-Sayed
authors: el-S
authors: Gad
mesh_terms: D002327:Cariostatic Agents / Q000737:chemistry*; D003722:Dental Alloys / Q000737:chemistry; D003799:Dental Stress Analysis; D004548:Elasticity / Q000187:drug effects*; D005460:Fluorides, Topical / Q000737:chemistry*; D006801:Humans; D008422:Materials Testing; D016382:Orthodontic Appliance Design; D009969:Orthodontic Wires; D013314:Stress, Mechanical; D013499:Surface Properties / Q000187:drug effects
chemical_list: D002327:Cariostatic Agents; D003722:Dental Alloys; D005460:Fluorides, Topical