Effects of reversing the coiling direction on the force-deflection characteristics of nickel-titanium closed-coil springs

• 발행기관: 대한치과교정학회
• 저자명: Hwan-Hyung Park Suk-Hwan Jung Juil Yoon Kwang Koo Jee Jun Hyun Han Seung-Hak Baek
• 간행물 정보: 『The Korean Journal of Orthodontics』제49권 제4호, 214~221쪽, 전체 8쪽
• 주제분류: 의약학 > 기타의약학
• 파일형태: PDF
• 발행일자: 2019.07.31

영문 초록

Objective: To investigate the effects of reversing the coiling direction of nickeltitanium 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 ± 1oC). 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.

목차

INTRODUCTION

MATERIALS AND METHODS

RESULTS

DISCUSSION

CONCLUSION

키워드

Nickel-titanium closed-coil spring Range of the force plateau Force-deflection characteristics Reversing the coiling direction