A representative ex-situ fretting wear investigation of orthodontic arch-wire/bracket contacts

Recent studies show that resistance to friction and wear between the arch-wire and the bracket are of great importance for the quality of orthodontal treatment. To optimize these phenomena specific surface treatments have been developed, but a major difficulty is the methodology for comparing and improving the given palliatives. A specific ex-situ fretting test has been developed which permits the micro-slidings generated by the occlusion movements to be superimposed on macro-slidings generated by the teeth displacement. In this study the friction force between brackets and arch-wires during combined macro-/micro-slidings has been investigated. Various stainless steel bracket/arch-wire contacts have been analyzed. The wear and friction properties of different PEPVD deposited coatings such as SiC and SiN have been studied under dry and wet artificial saliva conditions.