When coupled with rectangular archwires, they showed significantly lower F than Damon MX? and Time3? brackets, but similar F as the Vision LP? brackets. This behavior is probably associated with their design; their elastic properties decrease when coupled with thicker archwires, resulting in low Lapatinib chemical structure F. In contrast, self-ligating brackets have a built-in metal device (to close off the edgewise slot) that is rigid and rather stiff, compared to the soft and elastic surface of low-friction ligatures. Our findings are not in agreement with the general statement that self-ligating brackets generate lower F than conventional SS brackets,2,9,14�C15,17�C18,22 probably because a variety of different self-ligating brackets were tested, each with different mechanical characteristics:19 passive or interactive slots.
The differences among the passive and interactive SL brackets could be explained by the flexibility of the spring clip of active SL brackets that can actively engage the wire also in the presence of tipping.21 In addition, in this study, no significant differences were observed between the TMA, SS, and NiTi archwires in terms of F, although it was reported that TMA generates higher F than both SS and NiTi for all bracket-archwire combinations.2,23�C30 This variability may be due to the differences in the experimental setup, number of brackets, or bracket angulations.31 Therefore, a direct comparison of various published studies on this topic is complex. One limitation of this study is that it was carried out under ideal conditions, in a passive configuration with no misalignment of brackets, as shown by previous reports.
2,9,17,20,21,24�C25,29�C30 CONCLUSIONS Self-ligating brackets appear to be a family of very different brackets. For majority of the bracket-archwire combinations, the F values obtained with all 10 brackets ligated were significantly higher than those obtained with only the terminal brackets ligated; no significant differences were observed in only 4 cases, i.e., when Damon MX? and Vision LP? brackets were engaged with round archwires. Coupled with round archwires, Damon MX? and Vision LP? brackets generated significantly lower F than Victory Series?, Time3?, and Slide? ligature brackets, while Victory Series? brackets generated significantly higher F than all the other groups.
Coupled with rectangular archwires, Victory Series? brackets, Slide? ligatures, Cilengitide and Vision LP? self-ligating brackets generated significantly lower F than Time3? and Damon MX? brackets. However, as these findings do not actually reflect the situation in clinical use wherein the periodontal ligament provides ��give,�� the possibility of making any clinical extrapolation from this study is limited.
Light emitting diode (LED) light curing units are becoming increasingly popular in dental practice. Most of the first-generation LED light units were unable to cure composite resin in the manner of quartz-tungsten-halogen (QTH) light sources.