Abstract

The purpose of this study was to evaluate the effects of heat treatment on thermally activated nickel titanium archwires, and to determine the differences between wires from individual manufacturers. Thermally activated, nickel titanium wires were obtained from five different manufacturers in the 0.016 x 0.022 format. All wires were measured with a micrometer to determine their exact dimensions. Half of the wires were heat treated with the use of the Orthotherm Bending Art Programmer from Syrinx Medical Technologies (Berlin, Germany) while the other half served as a control. By passing an electrical current through the wires for a predetermined period of time, the wires were set to a "golden straw-yellow color" as per the manufacturers directions. Through the use of Differential Scanning Caliorimetry (DSC), tensile, and three-point bend testing, the following results were obtained: (1) The Temperature Transition Range (TTR) from the inactive martensitic state to the active austenitic state is slightly decreased by the heat treating process. This gives the clinician a slightly smaller TTR when initially placing the wire. (2) The required loading force for the nickel titanium wires tested was not significantly affected by the heat treating process when subjected to 1 mm and 2 mm deflections, with the exception of a slight decrease in force with the Ormco 35° wire and a slight increase with the TP Orthodontics wire. (3) When subjected to stress of 4% or greater, the heat treated, thermally activated nickel titanium wires were not significantly affected with regards to their unloading force, with the exception of a slight increase in force with the TP Orthodontics and a near total loss of force with the Ormco 35° Copper Ni-Ti wire. (4) While thermally activated nickel titanium alloy is manufactured in only 2-3 places in the world, not all of the wires exhibited similar properties due to the variations in metallurgy and individual manufacturing processes. (5) The thermally activated nickel titanium wires tested were, on average, somewhat smaller than their stated values.

LLU Discipline

Orthodontics

Department

Dentistry

School

Graduate School

First Advisor

Craig Andrieko

Second Advisor

Joseph M. Caruso

Third Advisor

Willis Schlenker

Degree Name

Master of Science (MS)

Degree Level

M.S.

Year Degree Awarded

1999

Date (Title Page)

6-1999

Language

English

Library of Congress/MESH Subject Headings

Orthodontic Wires; Orthodontic Appliances; Orthodontics

Type

Thesis

Page Count

vii; 49

Digital Format

PDF

Digital Publisher

Loma Linda University Libraries

Usage Rights

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.

Collection

Loma Linda University Electronic Theses and Dissertations

Collection Website

http://scholarsrepository.llu.edu/etd/

Repository

Loma Linda University. Del E. Webb Memorial Library. University Archives

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