Abstract

Bonded orthodontic brackets were introduced in the early 1960's and, since then, spontaneous debonding has been a constant nemesis. Consequently, many studies involving bond strength have been performed targeting brackets, adhesives, curing methods and types of teeth. The purpose of this study was to compare the properties of adhesive resins that have been experimentally modified in both the filler and the polymer.

Twenty different types of adhesives were prepared with variations in the ratios of the two different fillers (ground glass and Wollastinite fiber) and the polymer. System 1+ was used as a control since it was the original resin from which the experimental ones were modified. A tensile button bond strength test was performed on the twenty experimental groups, as well as on the control group. The physical properties of the experimental resins were then examined using specimens with typical engineering dog bone geometry. The information gained from this test included ultimate tensile strength, strain to failure, modulus of elasticity and resilience.

Sixteen of the twenty experimental groups had bond strengths greater than that of the control group. The button test produced fifteen equivalent groups. The dog bone test for ultimate strength produced fifteen similar groups. The dog bone strain to failure test produced eight equal groups. The dog bone modulus of elasticity test produced one group as superior and another ten groups tied for second place. Resilience was also studied. It was determined that the material with an Acrylic Terminated Polyurethane level of 70% and a filler ratio of 50/50 had the highest resilience value.

The conclusions obtained were:

  1. All experimental groups had a higher bond strength than the control group except for the four groups with a filler ratio of 100% Wollastonite fiber and 0% ground glass. These could be used, in vitro, to provide a higher bond strength than that provided by System 1+.
  2. No specific distinctions could be made for the effect of ATPU or filler ratio in regard to peak stress and strain.
  3. Higher resilience values were noted as the ATPU and ground glass were increased.
  4. Resilience was not related to the bond strength.
  5. Higher resilience was not detrimental to bond strength.

LLU Discipline

Orthodontics

Department

Dentistry

School

Graduate School

First Advisor

Craig A. Andreiko

Second Advisor

Joseph M. Caruso

Third Advisor

Daniel A. Flores

Fourth Advisor

Jay S. Kim

Degree Name

Master of Science (MS)

Degree Level

M.S.

Year Degree Awarded

2002

Date (Title Page)

8-2002

Language

English

Library of Congress/MESH Subject Headings

Adhesives; Dental Cements; Orthodontic Appliances; Dental Bonding

Type

Thesis

Page Count

x; 61

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

Download

Share

COinS