THE FRICTIONAL COEFFICIENTS IN TI-NB ALLOY
Takada, Megumi Nihon University
Nakajima, Akira Nihon University
Shimizu, Noriyoshi Nihon University
Ti-Nb alloy wire
Dynamic frictional force
Objectives: To determine the frictional force (FF) of the novel, elastic, bendable titanium-niobium (Ti-Nb) alloy orthodontic wire in stainless steel (SS) brackets and to compare it with those of titanium-nickel (Ti-Ni) and titanium-molybdenum (Ti-Mo) alloy wires.
Materials and Methods: Three sizes of Ti-Nb, Ti-Ni, and Ti-Mo alloy wires were ligated with elastic modules to 0.018-inch and 0.022-inch SS brackets. The dynamic FFs between the orthodontic wires and SS brackets were measured at three bracket-wire angles (0゜, 5゜, and 10゜) with an Instron 5567 loading apparatus (Canton, Mass).
Results: FFs increased gradually with the angle and wire size. In the 0.018-inch-slot bracket, the dynamic FFs of Ti-Nb and Ti-Ni alloy wires were almost the same, and those of the Ti-Mo alloy wire were significantly greater (P<0.05). FF values were 1.5–2 times greater in the 0.022-inch-slot bracket than in the 0.018-inch-slot bracket, regardless of alloy wire type, and the Ti-Mo alloy wire showed the greatest FF. Scanning electric microscopic images showed that the surface of the Ti-Mo alloy wire was much rougher than that of the Ti-Ni and Ti-Nb alloy wires.
Conclusion: These findings demonstrate that the Ti-Nb alloy wire has almost the same frictional resistance as the Ti-Ni alloy wire, although it has a higher elastic modulus.
The Angle Orthodontist
The EH Angle Education and Research Foundation
Open Access Journal
ango_88_5_602.pdf 954 KB