In vitro evaluation of physical vapor deposition coated beta titanium orthodontic archwires

Abstract

Objective: To determine in vitro the frictional properties, surface morphology, and load deflection rate with looped designs of two newly developed titanium aluminum nitride (TiAlN) and tungsten carbide/carbon (WC/C) physical vapor deposition (PVD) coated beta titanium orthodontic archwires coated with PVD. Materials and Methods: Frictional properties with Tidy’s protocol, surface evaluation before and after friction testing with the help of scanning electron microscopy (ESEM), and load deflection rate with different orthodontic loops on Instron universal testing machine were evaluated. Results: The results clearly indicate reduced frictional properties for WC/C coated archwires when compared with uncoated and TiAlN coated archwires. There were no significant surface alterations upon ESEM evaluation of friction tested archwires. Low load deflection rate was exhibited by both coated archwires, the difference in load deflection rate between the coated and uncoated archwires was statistically significant. Conclusion: WC/C coated wires can be recommended for even sliding mechanics due to reduced frictional properties, better surface characteristics, and low load deflection rate compared with TiAlN coated and uncoated archwires. (Angle Orthod. 2012;82:22–29.)