elastic properties of orthodontic wires

Dr. Robert KusyDr. Alan R. Greenberg

Elastic Properties of Orthodontic Wires

This study uses a series of formulae to compare different metal wires with regards to Elasticity

This journal is a comparative study on the Elastic Property of the following wires:

1. Stainless Steel (S.S.)2. Cobalt-Chromium (Co-

Cr)3. Nickel-Titanium (Ni-Ti)4. Beta-Titanium (B-Ti)

Journal Summary

Elastic Properties of Orthodontic Wires

Elastic Property Ratios

Three Basic Elastic Properties

1. Strength2. Stiffness3. Range

Stress States1. Bending2. Torsion

Elastic Properties of Orthodontic Wires

General Expressions

These properties are based on only the linear portion of the stress-strain curve

strength = stiffness x range

Journal Report | UP MS Orthodontics

Bending Strength RatioTo compare wire Y

with wire X and the formula that corresponds to the shapes in question

Journal Report | UP MS Orthodontics

Bending Stiffness RatioGeneral bending

stiffness ratio formulae

Journal Report | UP MS Orthodontics

Bending Range RatiosGeneral bending

range ratio formulae

Journal Report | UP MS Orthodontics

Torsion Strength RatiosGeneral torsion

strength ratio formulae

Journal Report | UP MS Orthodontics

Torsion Range Ratios General tensional

stiffness ratio formulas

Journal Report | UP MS Orthodontics

Torsion Stiffness RatiosGeneral torsional

range formulas

Journal Report | UP MS Orthodontics

ResultsElastic Property Ratios

are seen in Tables 4-10 for each S.S. Wire and B-Ti Wire configuration

Data AnalysisThe following charts

are expressed using Thurow’s work to better understand the outcome of the experiment.

Journal Report | UP MS Orthodontics

Journal Report | UP MS Orthodontics

Journal Report | UP MS Orthodontics

Journal Report | UP MS Orthodontics

Journal Report | UP MS Orthodontics

Journal Report | UP MS Orthodontics

Journal Report | UP MS Orthodontics

Journal Report | UP MS Orthodontics

Summary and ConclusionsNiTi makes the most active levelling wireB-Ti is a superior intermediate archwire where

flexibility is requiredS.S. and Co-Cr are wires of choice for stability

and where stability of form is required.