The self-ligating brackets are here to stay. Its most rudimentary design was the Russell appliance described by Dr. Jacob Stolzenberg in 1935, but it was not until the 1970s that manufacturers resumed interest in this type of bracket and began to incorporate new technologies. But what are self-ligating brackets and what types are there? What advantages does the self-ligating system have over conventional brackets? Why is friction important in orthodontic treatment? We tell you about this and much more in this article. Keep reading!
Source: Ortho Technology
What are self-ligating brackets?
The self-ligating brackets are those in which you do not need to use elastic or metallic ligatures because they incorporate in their design a closing mechanism (clip, lid or gate) that keeps the archwire in the slot of the bracket. The system was designed to dispense with ligatures, save time and provide less friction, which would allow more efficient sliding mechanics and ultimately reduce treatment time.
In turn, self-ligating brackets can be classified into active, passive and interactive, depending on their closing mechanism:
- Active self-ligating brackets: they have a closing spring that presses the archwire towards the bottom of the bracket slot, this is useful to have greater control of rotation and torque movements.
- Passive self-ligating brackets: their closing mechanism does not invade the slot or exert any active force on the arch.
- Interactive self-ligating brackets: in the initial stages of treatment with light archwires, the closing mechanism does not exert any pressure on the archwire; later, as the thickness of the archwire increases, the mechanism begins to be active for greater torque control.
Self-ligating brackets versus conventional brackets
The main advantages of the self-ligating system compared to the conventional brackets system are:
- The self-ligating system produces less friction between the bracket and the archwire, thus aligning and closing spaces is faster.
- In some cases of crowding, extractions can be avoided, because this less friction achieves a greater expansion of the arches with less incisal proclination, since in the alignment phase the arch can slide more easily backwards.
- Patient chair time is reduced, appointments are shorter and fewer in number, reducing overall treatment time and improving patient comfort.
Image: 1. Conventional ligating bracket. 2. Self-ligating bracket.
The importance of friction in orthodontics
Friction is broadly defined as the resistance that opposes motion when one object moves tangentially past another. This is what happens in a conventional orthodontic treatment in which tangential friction occurs between the bracket and the arch, and between the arch and the ligature. These elements cause a friction that can prevent the movement that is required, therefore, the force that needs to be applied must overcome that friction force in order to generate movement in the tooth.
Unfortunately, measuring these degrees of friction between archwires, brackets and ligatures is very difficult to perform in vivo and most of the currently available literature is based on in vitro studies, with its consequent lack of accuracy with real clinical situation, where other factors are also involved, such as the different degrees of malocclusion, the thickness of the periodontal ligament, the differences in masticatory forces, the rotations, the torque and the bracket-arch interface, the angulation of the bracket-arch, the temperature , etc.
What many studies do agree on is that whatever bracket is used, when the caliber of the archwire is increased, friction increases, however, self-ligating brackets used with rectangular archwires produce considerable friction less compared to conventional brackets.
We could conclude that there is indeed scientific evidence that self-ligating brackets generate less friction than conventional brackets, even in combination with rectangular archwires and with tip and torque present, however, it is still required to specify the results of clinical studies to prove the real benefits of self-ligation and for this, in vivo studies with long-term follow-up are required.
What are the factors that affect the resistance to friction in an orthodontic treatment?
The nature of friction in orthodontics has multiple factors. A large number of variables are mentioned in the literature that can directly and indirectly affect the levels of friction at the bracket-arch interface. These variables that influence friction resistance in sliding mechanics range from physical factors such as the type of brackets, wire properties, bracket-arch angulation, type of ligatures, etc., to < strong> biological factors, such as dental malposition, intraoral forces, stick-slip phenomenon, saliva, acquired film, etc.
Why is it important to reduce friction in orthodontic treatment?
Mainly because the friction produced by the system of forces generated by fixed appliances in orthodontics is directly proportional to the inflammatory response of periodontal tissues and roots, therefore, this is the purpose of self-ligating brackets , reduce friction, since these generate significantly less static and kinetic frictional force than conventional stainless steel brackets.
And you? Do you prefer self-ligating orthodontics or conventional orthodontics? If you have already switched to the self-ligating system, you use it with some of your patients or you want to start using it, at Dentaltix we have a set of brackets that you are going to love. Here it is!
Set of self-ligating metal brackets Roth or MBT Vidu
- Set of 28 units
- Ultra-slim design and low profile
- Slider Clip
- Passive self-ligating
- Decreases friction
- Shorter treatments
- Zero plastic footprint
See set of Vidu self-ligating brackets!
We hope our article has been useful to you, remember that if you want to always be up-to-date on the main news in the dental sector, all you have to do is follow us on our social networks and stay tuned for our next articles. Also, if you have questions regarding this or any other topic related to dental materials and equipment, we will be happy to help you. See you soon!