Scanning electron microscope appearances of fretting in the fixed orthodontic appliances

Fretting is one of the types of a tribologic wear. It is a process that occurs at a nominally immovable junction of elements. In dentistry, such elements can be brackets and archwires of fixed orthodontic appliances. They meet all the criteria for fretting to occur, i.e., they are nominally immovable, are subjected to initial loadings and they work in aggressive environment. Chrome-nickel stainless steel Elite Opti-Mim brackets (Trachem) working in vivo in oral cavity environment in combination with NiTi and stainless steel archwires were investigated. Scanning electron micrographs of bracket's working surfaces showed the presence of fretting damaged areas. This research also confirmed that there were almost all the types of fretting wear on the elements of the orthodontic appliances under examination.