Department of Orthodontics Dental Institute of King's College London, UK.
Eur J Orthod. 2010 Dec;32(6):741-6. doi: 10.1093/ejo/cjq017. Epub 2010 Jun 13.
The aim of the study was to examine, in vitro, the effect of a vertical force on the debond force and deformation of two multi-stranded wires bonded to the lingual enamel of lower incisor teeth. Two different stainless steel wires were used, 0.016 × 0.022 inch (Bond-A-Braid® Reliance Orthodontic Products) and a three-stranded 0.0175 inch wire (Ortho Technology). An in vitro model was used to simulate a vertical force at the interdental wire. Twenty-six pairs of incisors were placed in two groups. A 15 mm length of wire was bonded to the lingual surfaces of each pair of incisors using a common bonding technique. A vertical force was applied to the midpoint of the interdental wire, using an Instron universal testing machine. The failure characteristics examined included the maximum force for debond, the degree of wire deformation, and the site of failure. Significance was predetermined at P < 0.05 and multiple comparisons indicated no significant differences (P = 0.147) in the initial mean bond strength between the 0.0175 inch (41.44 N) and 0.016 × 0.022 inch (37.70 N) wires. The main failure type for both the initial and second debond events was fracture of composite bond at the wire-composite interface, cohesive failure. Both wires exhibited similar mean degrees of deflection of 1.30 and 1.51 mm for the 0.0175 inch and 0.016 × 0.022 inch wires, respectively. Rebonding to enamel resulted in significantly lower (P = 0.001) mean bond strength for both wires, 0.0175 inch (13.86 N) and 0.016 × 0.022 inch (14.17 N) in comparison with the initial bond strength. Rebonding to previously bonded enamel may be unpredictable and may lead to higher failure rates of bonded lingual retainers.
本研究旨在体外检测垂直力对两根多股结扎丝在离体下颌切牙舌侧釉质粘结的粘结力和变形的影响。使用了两种不同的不锈钢丝，0.016×0.022 英寸（Bond-A-Braid® Reliance Orthodontic Products）和 0.0175 英寸三股丝（Ortho Technology）。体外模型模拟了牙间结扎丝的垂直力。将 26 对切牙分为两组。用常规粘结技术将 15mm 长的结扎丝粘结到每对切牙的舌面。用 Instron 万能试验机在牙间结扎丝中点施加垂直力。检查的失效特征包括最大粘结力、丝变形程度和失效部位。显著性预先设定为 P<0.05，多重比较表明 0.0175 英寸（41.44N）和 0.016×0.022 英寸（37.70N）丝的初始平均粘结强度之间无显著差异（P=0.147）。两种丝的初始和二次脱粘的主要失效类型均为丝-复合粘结剂界面的复合粘结剂断裂，即内聚性失效。0.0175 英寸和 0.016×0.022 英寸丝的平均挠度分别为 1.30mm 和 1.51mm。与初始粘结强度相比，重新粘结到釉质时两种丝的粘结强度均显著降低（P=0.001），0.0175 英寸（13.86N）和 0.016×0.022 英寸（14.17N）。重新粘结到之前粘结的釉质可能是不可预测的，并且可能导致粘结舌侧保持器的失败率增加。
