A comparative evaluation of the physical properties of two orthodontic archwires

Abstract

IntRoductIonArchwires constitute the engine of modern orthodontic appliances as they directly determine the characteristics of force generation and consequently of tooth movement. Since the turn of the century, several materials such as gold, stainless steel, chrome-cobalt, nickel titanium, substituted titanium alloys, and recently polymeric materials have been in use for the construction of orthodontic archwires. Regardless of the advancements in materials, stainless steel is still the current choice in many clinical situations by virtue of its properties, economics, and practicality. [1] The A. J. Wilcock (AJW) archwire (A.J. Wilcock Scientific and Engineering Company, Whittlesea, Victoria, Australia), synonymously called the Australian archwire, has been the mainstay of all aspects of Begg orthodontic technique historically. The Australian archwire is basically high-tensile stainless steel wire that is heat treated to yield excellent clinical properties, which makes it an essential part of any modern orthodontic practice. [2] A. J. Wilcock Scientific and Engineering Company, the manufacturers of Australian wires, had introduced archwires in sizes ranging from 0.010″ to 0.024″ and grades of regular, regular plus, special, special plus, premium, premium plus, and supreme. [3] Recently, pulse straightening method has replaced the conventional spinner straightening method, which produces a far superior wire in terms of physical properties, smoother surface finish, and lesser frictional resistance. The difference in grades of these wires is associated with difference in resiliency and toughness. [4] The premium plus and supreme grades of wires are highly resilient. The larger sizes of these wires are recommended for use during correction of deep bite and maintaining arch form and lower size wires for forming mini-uprighting springs, aligning, etc. [5] Another company Ortho Organizers Inc., 1822 Aston Ave, Carlsbad, CA (Ortho.Org) has made available Australian archwires of diameters 0.010″,