Which of the following wires cannot be soldered and welded?

 # Which of the following wires cannot be soldered and welded?

A. Beta titanium

B. Optiflex wire

C. Gold wire

D. Stainless steel

The correct answer is B. Optiflex wire.

Optiflex arch-wire is composed of a silicon dioxide core, which provides the force or resiliency to the wire. The silicon resin forms the middle layer. This adds strength to the wire. The nylon outer layer makes the wire stain resistant. 

• Optiflex wire cannot be soldered, or welded, and a sharp bend cannot be placed in the wire. 

• It is a new aesthetic archwire. 

• Highly resilient, and effective for the alignment of crowded teeth. 

Another type of wire which cannot be soldered and welded is NiTi wire.