Friction in Sliding Orthodontic Mechanics: Ceramic Brackets, Teflon-Coated Wires and Comparative Resistances

In response to patient demand for more esthetic orthodontic appliances, brackets of aluminum-oxide ceramics and Teflon-coated archwires and ligature wires are now available to the practitioner. The round, coated archwires are potentially useful during cuspid retraction procedures in bicuspid-extraction orthodontic treatment. Controlled evaluation of frictional forces associated with the ceramic brackets and coated archwires compared to conventional appliances components of stainless steel has apparently not been reported in the literature to date. The objective of the present investigation was to measure and compare the magnitudes of frictional forces generated within a relevant sample of brackets, archwires, and ligations during simulated orthodontic edgewise sliding mechanics. Independent variables and their values were 1 bracket stainless steel, single-crystal ceramic, and polycrystalline ceramic, 2 archwire uncoated and Teflon-coated stainless steel, and 3 ligation uncoated and Teflon-coated stainless-steel wires. With coated or uncoated archwires, polycrystalline brackets generated larger frictional forces than either stainless-steel or single-crystal brackets. Teflon-coated archwires in slots of either ceramic bracket generated smaller frictional forces than uncoated archwires, although the ceramic brackets tended to cause greater distressing of the surfaces of both archwires than did the stainless-steel brackets. Theses.