Orthodontic Wires

ANSI/ADA Standard No. 32 Executive Summary

What is ANSI/ADA Standard No. 32 about?

This standard gives requirements and test methods for wires to be used in fixed and removable orthodontic appliances. It also gives the requirements for what information needs to be provided to the consumer on the labeling and packaging of the products for informed decision making.

What are the requirements I should know about for orthodontic wires?

Orthodontic wires are classified on the basis of their elastic behavior.

a)    Type 1 wires displaying linear elastic behavior during unloading at temperatures up to 50 °C.
b)    Type 2 wires displaying nonlinear elastic behavior during unloading at temperatures up to 50 °C.

ANSI/ADA Standard No. 32 sets requirements for dimensional, material (including composition) and mechanical properties as follows:

Mechanical properties – Type 1 wires   
The cross-sectional dimension (diameter, width, height and diagonal, as applicable); the composition including hazardous elements; and mechanical properties in tensile mode for modulus of elasticity, 0.2 % proof strength, and percentage elongation to fracture and in bending mode the force deflection rate.

Mechanical properties – Type 2 wires
The cross-sectional dimension (diameter, width, height and diagonal, as applicable); the composition including hazardous elements; austenite-finish temperature; and mechanical properties in bending mode for the force magnitudes measured during unloading at deflections of 3.0 mm, 2.0 mm, 1.0 mm and 0.5 mm and the permanent deflection after unloading

What's the bottom line?

ANSI/ADA Standard No. 32 sets detailed requirements concerning the presentation of the physical, chemical and mechanical properties of wires used in fixed and removable orthodontic appliances, the test methods by which they can be determined and packaging and labeling requirements.