EVALUATION OF TORQUE MOMENT IN ESTHETIC BRACKETS
Nakano, Taiji Nihon University
Nakajima, Akira Nihon University
Watanabe, Hiroto Nihon University
Osada, Ayaka Nihon University
Namura, Yasuhiro Nihon University
Yoneyama, Takayuki Nihon University
Motoyoshi, Mitsuru Nihon University
Objectives: To examine the torque moment that occurs between esthetic brackets and bendable alloy (stainless steel [SS], titanium-molybdenum [Ti-Mo], and titanium-niobium [Ti-Nb]) wires.
Materials and Methods: This study examined ceramic (CR), zirconium oxide (ZC), polycarbonate (PC), and conventional metallic brackets (MT) (upper, 0.018-inch and 0.022-inch slots) combined with SS, Ti-Mo, and Ti-Nb wires using elastic module ligation. The torque moments delivered by various wire and bracket combinations were measured using a torque gauge apparatus. The wire torque angles at 5–40° were examined.
Results: The torque value increased in the order of CR, ZC, MT, and PC brackets for both 0.018-inch and 0.022-inch slots. The fracture points of the CR and ZC brackets combined with SS and Ti-Mo wires were approximately more than 30° and 35°, respectively. No fracture points were detected in the combination of ZC brackets and Ti-Nb wires.
Conclusions: The current study identified the material characteristics of CR, ZR, and PC brackets during torque tooth movements. The present results demonstrate a characteristic combined effect between different esthetic brackets and bendable alloy wires.
The Angle Orthodontist
The EH Angle Education and Research Foundation
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