Aim: Variation in the surface roughness of archwires not only leads to more accumulation of plaque but also modifies the coefficient of friction. This necessitated for the present study to evaluate the surface characteristics of 0.016 × 0.022-inch nickel-titanium, beta-titanium, and copper-nickel-titanium archwires, before and after their use in the oral cavity using atomic force microscopy.
Materials and methods: The control and experimental samples were measured at three different positions under atomic force microscopy. The surface roughness was measured using roughness average, root mean square, and maximum height before and after use in the oral cavity among 60 adult participants. Data were analyzed using a one-way analysis of variance and Student's t tests using the Statistical Package for Social Software (SPSS) v.20.0.
Results: The surface roughness of archwires increased considerably after their clinical use compared to controls for nickel-titanium (p = 0.013) and beta-titanium (p = 0.002). A similar trend was noticed for root mean square where nickel-titanium (p = 0.014) and beta-titanium (p = 0.013) had increased root mean square. Maximum height was also noticed in nickel-titanium (p = 0.031) and beta-titanium (p = 0.016).
Conclusion: Surface roughness and the level of friction of the orthodontic wires increase significantly for nickel-titanium and beta-titanium after the clinical use. There is a difference in increase of surface roughness of the archwire within and between the bracket slots.
Clinical significance: Nickel-titanium and beta-titanium wires show more roughness and resultant higher friction levels after use in the oral cavity. Hence, care related to plaque accumulation is essential.
Keywords: Beta-titanium; Copper-titanium; Nickel-titanium; Orthodontics Surface roughness..