What type of arch wire is referred to as a "working arch wire"?

The term "working arch wire" refers to stainless steel arch wires. This is because stainless steel has the unique properties needed for comprehensive tooth movement and stability in orthodontic treatment.

Stainless steel is known for its strength and rigidity, which allows it to effectively transmit forces to the teeth. During orthodontic treatment, the working arch wire is crucial as it holds the brackets in place and facilitates the precise movement of teeth into their desired positions. Its strength also aids in resisting deformation, making it suitable for the active phase of tooth movement.

In contrast, other types of arch wires have specific uses: nickel titanium is typically used for initial alignment due to its flexibility and shape memory, while round wires are often used in earlier phases of treatment or for specific adjustments. Beta titanium, though useful for its flexibility and light force application, is not primarily classified as a working arch wire in the typical sense. Hence, stainless steel is recognized as the definitive working arch wire in orthodontics.