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. Materials and 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). 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. © 2012 by The EH Angle Education and Research Foundation, Inc.