Abstract

In this study, the shear bondstrengths of five commercially available orthodontic light-cured adhesives were evaluated with respect to two types of curing lights and various cure-times. A total of 160 Transcend brackets (mechanical retention) were utilized. The brackets were individually bonded to knurled stainless steel testing rings via the respective adhesives. Each bracket was sheared from the testing ring using an Instron machine. For each adhesive a 2, 5, 10, and 20 second cure-time, and an immediate, 5 minute, 20 minute, and 24 hour shear test time was employed. The adhesives were cured using high intensity and low intensity visible light curing units.

Each adhesive was evaluated for clinically acceptable bondstrength in relation to cure-time and dark cure-time.

The results indicated that the level of light intensity of the curing unit, irrespective of the length of cure or point in time of the shear test, was a significant factor pertaining to the level of bondstrength for all the adhesives tested except adhesive SP.

Overall, the adhesives demonstrated a significant increase in bondstrength following a single light exposure after a 24 hour period. This established the presence of dark curing ability. The results also seem to suggest the presence of a minimum threshold requirement of light exposure before a specific adhesive can adequately express its dark cure ability.

It was shown that for each adhesive, the length of cure-time strongly influenced the level of bondstrength achieved. Among the adhesives, significant variability in bondstrength attainment was demonstrated over cure-time.

LLU Discipline

Orthodontics

Department

Dentistry

School

Graduate School

First Advisor

Joseph M. Caruso

Second Advisor

Daniel A. Flores

Third Advisor

David R. Rynearson

Fourth Advisor

Michael J. Fillman

Fifth Advisor

M. Toufic Jeiroudi

Sixth Advisor

Willis L. Schlenker

Seventh Advisor

Grenith Zimmerman

Degree Name

Master of Science (MS)

Degree Level

M.S.

Year Degree Awarded

1992

Date (Title Page)

8-1992

Language

English

Library of Congress/MESH Subject Headings

Cementation -- methods; Dental Cements -- analysis; Light; Materials Testing -- methods

Type

Thesis

Page Count

iv; 42

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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