60 degree temperature control nitinol wire compared with 80 degree temperature controlled nitinol.
Nitinol wire alloy is a shape memory alloy, which is a special alloy that can automatically restore its plastic deformation to its original shape at a certain temperature. Its expansion rate is over 20%, fatigue life is up to 107 times, damping characteristics are 10 times higher than ordinary springs, and its corrosion resistance is better than the current best medical stainless steel, so it can meet the needs of various engineering and medical applications. It is a very good functional material.
In addition to its unique shape memory function, memory alloys are also resistant to wear, corrosion, high damping and superelasticity.
Clinical application of nitinol wire:
1. Early alignment and flattening of the patient’s dentition Due to the superelasticity and shape memory properties of the Nitinol archwire and the low stress-strain curve, the Nitinol archwire is routinely included as the initial phase in the correction system. The archwire, in this way, the patient’s discomfort will be greatly reduced. Due to the existence of several different straight wire bowing techniques, MBT technology recommends the use of 0.016 inch heat activated Nitinol arch wire (HANT wire). The DEMON self-locking bracket technology recommends the use of copper-containing heat activated nickel-titanium produced by Omcro. Alloy arch wire (phase transition temperature is about 40 degrees), O-PAK correction technology is recommended to use 0.016 inch superelastic nickel-titanium alloy arch wire for early alignment.
2. Nickel-titanium spring: Nickel-titanium push spring and tension spring are springs used for orthodontics of teeth. They are special for nickel-titanium superelasticity. They are suitable for orthodontic treatment to develop gaps between teeth and pull teeth in different directions. A nickel-titanium coil spring elongated by 1 mm produces a force of approximately 50 g. Nickel-titanium coil springs have high elastic properties and produce a softer and stable durability under tension. The attenuation of the force is small and produces the ideal orthodontic force required to meet the clinically moving teeth. Meet physiological requirements. The nickel-titanium wire tension spring has a high degree of elasticity and a very low permanent deformation rate, and the release force of the same is different from that of the same diameter of the stainless steel wire by a factor of 3. 5 – 4 times. Therefore, in orthodontic treatment, the patient not only has mild pain, but also feels soft and lasting, and the time for re-diagnosis is reduced, the course of treatment is shortened, and the curative effect is improved. It is a new excellent mechanical device in orthodontic treatment.
3. L-H arch wire is developed by Dr. Soma of Japan and produced by Tomy. “LH” is named “Low Hysteresis”, that is to say, when the archwire is ligated to the bracket, that is, the stress generated when the archwire is activated and the tooth is slowly recovered when the tooth is moved. The difference in stress generated in the original state is small. The lag is small. SOMA et al. compared the stress-strain curves of LH archwires and other Ni-Ti alloy wires. The LH archwire has the smallest hysteresis range. This feature gives archwires the advantage of low load and sustained light force, while the initial slope of the curve is low. It shows that the rigidity of the archwire is low, and the hysteresis curve of the other types of Nitinol archwires indicates that the rigidity is large. It is obvious that the LH archwire has obvious mechanical advantages. Since the content ratio of titanium in the LH wire nickel-titanium component is higher than that of the general nickel-titanium arch wire, it is called titanium-nickel wire, and experiments have proved that the shock absorption effect is strong. Another feature of LH nickel-titanium wire is that it can be bent and can be heated and shaped by heat treatment equipment, so LH nickel-titanium wire can also be leveled.