Orthodontic wire may be heat treated to relieve residual stresses resulting from the formation of bent configurations. This study utilized electronic equipment to detect and record the initial amount of activation force, and the amount of force lost due to the intrinsic properties of the wire. The information was gathered at three hour intervals over fifteen one-week periods. The data were statistically analyzed by a computer to deter mine means and standard deviations. A general linear hypothesis was utilized to test covariants and the main effects.
A total of forty-eight wires were tested. Closed he lix retraction springs fabricated from .016" X .016" Blue Elgiloy, Permachrome Standard, and Multiphase were tested in non-heat treated and heat treated conditions. Hilgers retraction springs fabricated from .016" X .016" Blue Elgiloy were tested in a non-heat treated state. Activation force for helical closing loop, retractors, Ricketts retractors, and Hilgers retractors and grey chain were observed.
The data indicated that without heat treatment Blue Elgiloy had greater force loss than Multiphase and Permachrome. However, after heat treatment of the three types of wires. Blue Elgiloy had less force loss than Permachrome and Multiphase. The effects of heat treatment for the three types of wires were statistically significant. Three methods for heat treatment of Blue Elgiloy were tested. Heat treatment of Blue Elgiloy using an oven, resistance or cigarette lighter, revealed no statistical differences.
The wire design of a helical closing loop versus a Hilgers retractor did not significantly decrease the amount of force lost in non-heat treated Blue Elgiloy. However, the wire design did affect the distance for activation. A Ricketts retractor had the greatest distance for activation of 150 grams. Hilgers retractor had inter mediate distance, and a helical closing loop had the least distance for activation. Grey chain activated 1 1/2 millimeters exerts a force of 195 grams. The force of activation decreased 66 grams at the end of 24 hours.
James R. Wise
Grenith J. Zimmerman
Joseph M. Caruso
Laurence A. Seifert
John E. Peterson
Master of Science (MS)
Year Degree Awarded
Date (Title Page)
Library of Congress/MESH Subject Headings
Orthodontic Appliances; Orthodontics, Corrective
Loma Linda University Libraries
This title appears here courtesy of the author, who has granted Loma Linda University a limited, non-exclusive right to make this publication available to the public. The author retains all other copyrights.
Dunn, Richard Earl, "Effects of Stress Relief to Decrease Force Loss in Retraction Springs" (1983). Loma Linda University Electronic Theses, Dissertations & Projects. 1249.
Loma Linda University Electronic Theses and Dissertations
Loma Linda University. Del E. Webb Memorial Library. University Archives