Recently, self ligating orthodontic brackets have become more popular. They have been around in one form or another for a while, but companies like GAC and 3-M have come out with more refined versions that have some sort of latch to hold the wire in place. The GAC shown here on the left has a clasp (shown in yellow) that moves up to hold the wire in place. We are begining to incorporate some of these into our orthodontic practice. One concern with traditional alastic ligatures or even wire ligatures is the difficulty of proper oral hygiene around the bracket area. The self ligating bracket provides some advantage in this area. The main advantage is that it will take less time to change wires. That means shorter orthodontic appointments for the patient and more efficiency for the doctor and staff. The only problem is that you can't get the cool colors available with alastics.
This one from 3-M has little C clasps on each side.
This ex-vivo study compared the static frictional resistance of three self-ligating brackets with a conventional steel-ligated Ultratrimm bracket. The effects of archwire size (0.020, 0.019 x 0.025 and 0.021 x 0.025-inch), bracket/archwire angulation (0, 5 and 10 degrees) and the presence of unstimulated human saliva were investigated. The study demonstrated that both increases in wire size and bracket/archwire angulation resulted in increased static frictional resistance for all bracket types tested, with the presence of saliva having an inconsistent effect. Mobil-Lock Variable-Slot had the least friction for all wires for 0 degree angulation. However, with the introduction of angulation, the values were comparable to those of the other brackets. Activa brackets had the second lowest frictional resistance, although high values were found with 0.019 x 0.025-inch wires. SPEED brackets demonstrated low forces with round wires, although with rectangular wires or in the presence of angulation, friction was greatly increased. Ultratrimm brackets produced large individual variation, confirming the difficulty in standardizing ligation force, although under certain conditions, significantly larger frictional forces were observed. In conclusion, self-ligating brackets showed reduced frictional resistance in comparison to steel ligated brackets only under certain conditions.
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