Date of Award

Spring 2004

Document Type

Thesis - Restricted

Degree Name

Master of Science (MS)

Department

Dentistry

First Advisor

Bradley, T. G.

Second Advisor

Berzins, David

Third Advisor

Villalobos, Erancisco

Abstract

Titanium orthodontic brackets have recently been introduced as a more biocompatible option to the traditional stainless steel. The purpose of this study was to determine the metallographic composition of two types of titanium brackets and two types of stainless steel brackets, analyzing both the base and wing structures of the brackets separately. The two titanium brackets were Orthos2 (Ormco, California, USA) and Rematitan (Dentaurum, Ispringen, Germany). The two stainless steel brackets were Orthos (Ormco, California, USA) and Equilibrium (Dentaurum, Ispringen, Germany). The four specimens were embedded in epoxy resin, ground with sandpaper, polished with alumina suspension, and finally coated with a layer of conductive carbon. The structure and morphology of each bracket was analyzed using a scanning electron microscope, and the elemental composition of the base and wing of each bracket was determined using energy dispersive spectrometry. The two injection-molded brackets (Rematitan and Equilibrium) showed uniform dispersion of elements throughout the entire bracket, while the two machine-milled brackets (Orthos and Orthos2) showed differing levels of metals according to the location. Orthos2 showed a composition of mainly titanium and a small amount of aluminum in the base, with small amounts of aluminum and vanadium in the wing. Orthos showed different percentages of metals in the base, wing, and in the gold-based brazing material itself which consisted of a significant amount of nickel, iron, and copper. Results from this research lead to questions of corrosion susceptibility based on the metallographic composition (of the brazing alloy in Orthos, in particular), as well as the strength of each bracket when comparing the elemental composition and bracket structure.

Share

COinS

Restricted Access Item

Having trouble?