Park, Hwan-Hyung Jung, Suk-Hwan Yoon, Juil Jee, Kwang Koo Han, Jun Hyun Baek, Seung-Hak 2024-01-19T19:34:24Z 2024-01-19T19:34:24Z 2021-09-02 2019-07 2234-7518 https://pubs.kist.re.kr/handle/201004/119838 Objective: To investigate the effects of reversing the coiling direction of nickel-titanium closed-coil springs (NiTi-CCSs) on the force-deflection characteristics. Methods: The samples consisted of two commercially available conventional NiTi-CCS groups and two reverse-wound NiTi-CCS groups (Ormco-Conventional vs. Ormco-Reverse; GAC-Conventional vs. GAC-Reverse; n = 20 per group). The reverse-wound NiTi-CCSs were directly made from the corresponding conventional NiTi-CCSs by reversing the coiling direction. Tensile tests were performed for each group in a temperature-controlled acrylic chamber (37 +/- 1 After measuring the force level, the range of the deactivation force plateau (DFP) and the amount of mechanical hysteresis (MH), statistical analyses were performed. Results: The Ormco-Reverse group exhibited a significant shift of the DFP end point toward the origin point (2.3 to 0.6 mm), an increase in the force level (1.2 to 1.3 N) and amount of MH (1.0 to 1.5 N) compared to the Ormco-Conventional group (all p < 0.001), which indicated that force could be constantly maintained until the end of the deactivation curve. In contrast, the GAC-Reverse group exhibited a significant shift of the DFP-end point away from the origin point (0.2 to 3.3 mm), a decrease in the force level (1.1 to 0.9 N) and amount of MH (0.6 to 0.4 N) compared to the GAC-Conventional group (all p < 0.001), which may hinder the maintenance of force until the end of the deactivation curve. Conclusions: The two commercially available NiTi-CCS groups exhibited different patterns of change in the force-deflection characteristics when the coiling direction was reversed. English KOREAN ASSOC ORTHODONTISTS Effects of reversing the coiling direction on the force-deflection characteristics of nickel-titanium closed-coil springs Article 10.4041/kjod.2019.49.4.214 1 KOREAN JOURNAL OF ORTHODONTICS, v.49, no.4, pp.214 - 221 KOREAN JOURNAL OF ORTHODONTICS 49 4 214 221 N scie scopus kci ART002488335 000476652900003 2-s2.0-85069930554 Dentistry, Oral Surgery & Medicine Dentistry, Oral Surgery & Medicine Article NITI ALLOY WIRE Nickel-titanium closed-coil spring Range of the force plateau Force-deflection characteristics Reversing the coiling direction