Effect of surface treatment on physical and mechanical properties of nickel-titanium orthodontic archwires by fine particle shot peening method

Abstract

© 2019 Trans Tech Publications, Switzerland Background: Surface treatment on metal can alter physical and mechanical properties. Understanding the physical and mechanical properties of the archwires is essential for the management of orthodontic treatment. Methods: This study used digital micrometer, universal testing machine, and surface hardness tester for measuring dimension, unloading force, and surface hardness of two different type of nickel-titanium (Ni-Ti) archwires: commercially available Ni-Ti (NT-N) and surface treated Ni-Ti by fine particle shot peening (FPSP) method (NT-F). Statistical analysis was undertaken using a paired T-test (α=0.05). Results: No significant difference was found on both vertical and horizontal dimensions of NT-N and NT-F (p= 1.00 and 0.796 respectively). For bending and surface hardness test, significance difference was found (p<0.001 and p<0.001 respectively). Conclusions: The NT-F archwire provided lower unloading force and surface hardness but there was no change in size when compared with NT-N.