An Energy-Dispersive X-ray Spectroscopy (EDX)- and Tensile Test-Based Investigation of Mechanical Properties and Elemental Analysis of Three Commercial Stainless Steel Orthodontic Archwires

Introduction: Stainless steel (SS) continues to be the preferred working archwire during orthodontic retraction. Inter-manufacturer differences and clinical preferences suggest that all brands of the same dimension do not perform identically. Hence, the objective of the study is to compare the elemental composition and mechanical properties of three commercially available SS archwire brands representing different economic tiers in the market: 3M Unitek (Monrovia, CA, USA; high tier), G&H Orthodontics (Franklin, IN, USA; medium tier), and DTech (Pune, India; low tier). Materials and methods: Seven specimens from each group (Group I: 3M; Group II: GH; Group III: DT) were subjected to scanning electron microscopic (SEM) evaluation coupled with elemental analysis using energy-dispersive X-ray spectroscopy (EDX). They were also subjected to tensile testing using a universal testing machine for evaluating ultimate tensile strength (UTS), yield strength (YS) and modulus of elasticity (E). Results: SEM evaluation showed variation in carbon concentration across the groups, with the highest in 3M (7.3%), followed by DT (5.5%) and GH (3.9%). UTS and YS were highest for 3M, followed by DT and GH. E was highest for DT, followed by GH and 3M. However, all values were statistically insignificant. Conclusion: The corrosion resistance of commercially available SS archwires may not be consistent with the expected material properties because of the marked variation in carbon content among brands. 3M might deform less in the oral cavity with better fracture resistance, indicating superior mechanical stability. DT exhibited greater stiffness, making it more useful in cases requiring occlusal plane control. GH demonstrated intermediate performance between the groups.