Braces are made up of three things: brackets, wires and ligatures. The ligatures are the dental elastics or “rubber bands” that are used to tie the wires in place. These are becoming more and more obsolete as new types of brackets are able to fulfill this function. In today’s piece, I want to speak a little about wires, and to talk a little about what thermal wires are and how they are used in orthodontics. Hopefully this way you can decide if getting thermal orthodontic wires is a good decision for you.
What archwires do
Archwires are the wires that run through the brackets on the entire row of teeth. They are sometimes accompanied by smaller wires that connect brackets or that are used for ligation. The main thing the archwire does is exert the energy; the wire creates the tension that is used to guide the teeth to their correct position.
Many different kinds of archwires exist, and one of the many, many types are thermal archwires. What differentiates them from standard orthodontic archwires?
Usually wires are tightened manually, through little screws that are on the brackets, or by being physically shortened and then wound to exert more pressure. But some wires can be activated thermally, as they will expand or contract to hot or cold temperatures. The wire is soft when it is cold, and as it gets warmer thermal wires will become hard. At body temperature they are just the right tightness, and by getting bigger or shorter wires the teeth can be guided to their correct place. The wires are made by taking the standard titanium alloy and adding higher amounts of nickel. These alloys are non-toxic and are not in the mouth for long enough to start leaching heavy metals into your system.
These wires are much better than the regular old ones but they are not without any negative properties. If you drink hot drinks, you may find your wire stiffening when you really did not mean for it to.
These wires also cost more money, and are not necessarily worth it from an economic point of view. Their main advantage is that the activation sessions are much more comfortable. Usually, after an activation your mouth will feel sore and painful for up to two days, and even after a few days it may still feel tight. With thermally activated wires, the wire becomes stiff over time, and not all at once, but in the course of an hour or so. The discomfort associated with tightening sessions only lasts a couple of hours, and if it is too tight, you can just drink some cold water and get temporary relief.