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Corrosion of Fixed Orthodontic Appliances: Causes, Concerns, and Mitigation Str...
Frois, António; Santos, Ana Cristina; Louro, CristinaThe orthodontic supply market is a prosperous billion-dollar industry, driven by an increasing demand for orthodontic appliances. The supremacy of metallic first-generation biomaterials is evident for manufacturing brackets, archwires, bands, and other components due to their well-recognized chemical inertness, spontaneous passivation, biocompatibility, and favorable mechanical properties combination. However, ...
Corrosion behaviour in artificial saliva of medical grade SS316L sputter-coated...
Frois, António; Faia, Pedro; Santos, Luis; Santos, Ana; Louro, C.ABSTRACT: Hydrogenated amorphous carbon (a-C:H) top layer was deposited onto 316L medical grade stainless steel by reactive magnetron sputtering with two types of interlayers, based on Cr and Ti. The goal was to evaluate the effect of the adhesion-promoting layers on the overall coating/substrate system. After the immersion test in acidic artificial saliva, no surface signs of corrosion were detected. However, ...
Metal Release and Surface Degradation of Fixed Orthodontic Appliances during th...
Frois, António; Mendes, Alexandra Ricardo; Pereira, Sónia Alves; Louro, Cristina SantosThe purpose of the present study is twofold: (i) to assess the salivary nickel, chromium, and iron concentrations and (ii) to characterize the surface microstructure of the typical commercially available Ni-containing metallic appliances during the first 12-week orthodontic treatment period. A total of 85 unstimulated saliva samples were collected from patients before treatment, after 2 days, and after 1, 4, an...
Corrosion behaviour in artificial saliva of medical grade SS316L sputter-coated...
Frois, António; Faia, Pedro; Santos, Luis; Santos, Ana; Louro, C.ABSTRACT: Hydrogenated amorphous carbon (a-C:H) top layer was deposited onto 316L medical grade stainless steel by reactive magnetron sputtering with two types of interlayers, based on Cr and Ti. The goal was to evaluate the effect of the adhesion-promoting layers on the overall coating/substrate system. After the immersion test in acidic artificial saliva, no surface signs of corrosion were detected. However, ...
Salivary pH Effect on Orthodontic Appliances: In Vitro Study of the SS/DLC System
Frois, António; Evaristo, Manuel; Santos, Ana Cristina; Louro, Cristina SantosStainless steels (SS) are the most-used alloys for manufacturing fixed orthodontic appliances due to their attractive set of mechanical properties, biocompatibility, and high corrosion resistance. Nevertheless, during regular orthodontic treatments–taking at least around 2 years–the intraoral environment inevitably degrades these bioalloys, releasing metallic ions into the oral cavity. In the first part of this...
Can a-C:H-Sputtered Coatings Be Extended to Orthodontics?
Frois, António; Aleixo, Ana Sofia; Evaristo, Manuel; Santos, Ana Cristina; Louro, CristinaHydrogenated amorphous carbon (a-C:H) coatings are attractive materials for protecting metallic surfaces in extreme biological environments like the human oral cavity, due to the unusual combination of mechanical properties, superior bioinertness, and relative easier and cheaper produc-tion. In this work, two a-C:H coatings were deposited on AISI 316L substrates by reactive magnetron sputtering with two CH4 flo...