Summary in English

Toxic elements may be released by corrosion of orthodontic appliances, contribute to adverse patient reactions. Previous studies have shown that the composition of orthodontic attachments is complex in that several different alloys are used in the same attachment. The close contact of alloys with different composition enhances the galvanic corrosion of the attachment in the oral cavity where saliva acts as an electrolyte. Self-engaging brackets facilitate the attachment of orthodontic wires and may increase the efficiency of the treatment. There is little information on the composition and corrosion resistance of self-engaging brackets are scarcely known. Ten different self-engaging brackets, six made from alloys and four made of composite and/or ceramic with an alloy locking part, were investigated, and the composition determined by EDAX in a scanning electron microscope. The analysis revealed a complex composition with several alloys in the same appliance, all contained nickel. The release of elements in the standardized corrosion test varied among the products, and for some products the total release of elements exceeded internationally recommended limits.

Reference
Korrosjon av selvligerende kjeveortopediske fester in vitro
Kjelland D, Syverud M, Kvam K, Dahl JE.
Nor Tannlegeforen Tid 2009; 119: 708–12

D Kjelland