Comparison of the fatigue limit of fiber-reinforced composites and stainless steel wires when attached to the tooth surface for anchorage reinforcement

Kim, Moon Jung; Park, Soo Byung

Abstract

This study was performed to compare the fatigue limit of stainless steel wires and Fiber-reinforced composites (FRC) under conditions of permitting physiologic tooth movement, and to evaluate the clinical value of FRCs which was used to reinforce the anchorage unit. The stainless steel wire groups were divided into round and rectangular wire groups. The FRC groups were divided into uni-directional and woven groups, with resin coating and without resin coating in the proximal area. After the number of cycles to failure of each of the 6 groups were measured within the 5 x 10(5) cycle fatigue limit simulating the orthodontic treatment period, the fatigue limit of each group was compared with each other. The findings of this study were as follows. In stainless steel wires, the fatigue limit of rectangular wires were higher than that of round wires. But there was no statistically significant difference (p > 0.05). In FRCs with resin coating and without resin coating in the interproximal area, the fatigue limit of uni-directional type was higher than that of the woven type (p < 0.05). In uni-directional and woven type FRCs, the fatigue limit of FRC with resin coating in the interproximal area was higher than that of FRC without resin coating (p < 0.05). As the FRCs and stainless steel wires did not fracture until the 5 x 10(5) cycle fatigue limit which clinically is useful, it is sufficient to use FRC and stainless steel wire for reinforcing anchorage. When esthetics is important and the attachment of additional devices are necessary, it seems sufficient to use FRC as anchorage reinforcement.