Comparison surface characteristics and chemical composition of conventional metallic and Nickel-Free brackets

Abstract

This study aims at comparing conventional and nickelfree metal bracket surface characteristics with elemental composition by scanning electron microscopy (SEM), using energy dispersive spectroscopy (EDS). The sample consisted of 40 lower incisor brackets divided into four groups: ABZ = conventional brackets, Kirium Abzil 3M ® (n = 10); RL = conventional brackets, Roth Light Morelli ® (n = 10); NF = nickel-free brackets, Nickel-Free Morelli ® (n = 10); and RM = nickel-free brackets, Roth Max Morelli ® (n = 10). Qualitative evaluation of the bracket surface was performed using SEM, whereby surface features were described and compared. The elemental composition was analyzed by EDS. According to surface analysis, groups ABZ and RL showed a homogeneous surface, with better finishing, whereas the surfaces in groups NF and RM were rougher. The chemical components with the highest percentage were Fe, Cr and C. Groups NF and MR showed no nickel in their composition. In conclusion, the bracket surface of the ABZ and RL groups was more homogeneous, with grooves and pores, whereas the surfaces in groups NF and RM showed numerous flaws, cracks, pores and grooves. The chemical composition analysis confirmed that the nickel-free brackets had no Ni in their composition, as confirmed by the manufacturer's specifications, and were therefore safe to use in patients with a medical history of allergy to this metal.

Surface analysis of metal clips of ceramic self-ligating brackets

“…Scanning electron microscopy (SEM) with energy-dispersive X-ray spectroscopy (EDS) has been widely used to analyze the surface chemical composition of bracket bodies 567. It can also be used to analyze the surface chemical composition of bracket clips.…”

Qualitative and Quantitative Evaluation of Different Types of Orthodontic Brackets and Archwires by Optical Microscopy and X-ray Fluorescence Spectroscopy

“…The release of wear products can be analysed using different methodologies [48,49], and this can make it difficult to compare the results with those of other studies. Furthermore, several researches have highlighted only the superficial changes of the orthodontic wires using scanning electron microscopy (SEM) without evaluating the quantity of ions released [50,51]. In this study, X-ray fluorescence spectroscopy (XRF) analysis was also performed for the chemical assessment of ions released from wear products.…”

Color heterogeneity and individual color changes in dentin and enamel bleached in the presence of a metallic orthodontic bracket

“…However, nickel acts as an anticorrosive agent, and nickel‐free brackets are more susceptible to corrosion 21 . Regarding its composition, the bracket used also contains approximately 62% Fe 2 O 3 , 22 which exhibits some catalytic behavior toward the decomposition of hydrogen peroxide 23 . Accelerating peroxide decomposition increases the oxidation of the brackets, and the release of some ions, such as manganese and iron, can result in staining on dental surfaces 24 .…”