The Study Of Self-ligation Bracket's Friction

With the application of sliding mechanism at the fixed appliance, the friction between brackets and arch wire was particularly important. The greater the friction was, the smaller the tooth movement ratio was. It affected the treatment results. So, how to reduce friction, get the most effective tooth movement and optimal biological tissue reaction became the hotspot of study. In recent years, the self-ligation bracket used spring clip or caps lock to entrap the arch wire instead of the conventional ligation. It significantly reduced the friction between the brackets and the arch wire. In this paper, the friction of self-ligation bracket appliance was reviewed.In orthodontic treatment, when the brackets and the arch wire had relative sliding or relative sliding trend, orthodontic friction was produced. Orthodontic friction was divided into static friction and dynamic friction. Orthodontic sliding greatly depended on static friction. The friction of self-ligation bracket appliance was mainly impacted by mechanical factors, biological factors and the effect of time. Most scholars believed that self-locking bracket appliance reduced the friction between the brackets and the arch wire and was more suitable for the sliding mechanism, so that light force correction could be realized and brought the doctor new ideas. The existence of friction decayed part of treatment force and effect tooth movement, so friction should also be considered in addition to the optimum force of tooth moving. Study of friction could accurately provide the correct reference to clinic plans. It had special clinical significance to the achievement of the rapid physical tooth moving and reducing the loss of anchorage.The development of self-ligation bracket appliance was a revolution of the orthodontic history. The self-ligation bracket appliance was inadequate, and scholars also held different views in some respects, but it decreased the friction, minimized the chair time and shortened the treatment duration. Such the advantages were obvious. It was an appliance worth being promoted.