Abstract

The intent of this paper was to: 1. Evaluate the mode of adhesive failure when debonding both flexible and rigid base orthodontic brackets. 2. Evaluate the bracket bases for enamel detachments. 3. Measure the enamel detachments.

After preforming shear test on flexible and rigid base orthodontic brackets mounted to extracted human teeth it was determined that failure occurred at the enamel/adhesive interface 30% of the time, at the bracket/adhesive interface 10% of the time and a combination of these 60% of the time for both groups.

Five brackets from each group were evaluated for enamel detachments using energy dispersive x-ray analysis. All the brackets showed evidence of calcium in the adhesive retained on their bases. Large enamel detachments were measured on some brackets using the scanning electron microscope. The size of these detachments ranged from 12.5 microns to 77.2 microns. Defects in the enamel surface corresponding to the enamel detachments on the bracket bases were located and documented with micrographs.

It was concluded that if adhesive is pulled from the enamel surface during the debonding procedure enamel detachments occur. The size of these detachments varies but they can be large enough to result in a sizeable defect in the enamel surface that is difficult to remove with polishing procedures. A debonding procedure that leaves the adhesive on the tooth surface followed with removal by previously tested methods is recommended to provide a consistent result.

Due to the small sample number and lack of statistical support, the data and conclusions presented should be viewed as a pilot study.

LLU Discipline

Orthodontics

Department

Dentistry

School

Graduate School

First Advisor

Lawrence W. Will

Second Advisor

Clelan G. Ehrler

Third Advisor

Virgil V. Heinrich

Fourth Advisor

Garland E. Scott

Fifth Advisor

Gerald Shavlik

Degree Name

Master of Science (MS)

Degree Level

M.S.

Year Degree Awarded

1984

Date (Title Page)

8-1984

Language

English

Library of Congress/MESH Subject Headings

Dental Bonding; Dental Enamel; Orthodontic Appliances, Removable

Type

Thesis

Page Count

2; vi; 35

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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