Abstract

Light cured adhesives have gained more popularity since their introduction more than three decades ago. Photo-polymerization allows more thorough curing on demand and thus facilitates better control of bracket placement. With new technologies, recently developed curing lights promise even more improvement. These systems are not only more sophisticated, but also more sensitive to the types of resins and clinical application. Specific comparison studies of the new systems in the orthodontic bonding are lacking because most of curing lights are originally designed for general dentistry.

This study evaluated the in-vitro ability of four curing lights to polymerize the Transbond XT bonding composite: the Demetron model VCL300 was selected to represent the standard halogen type; the Optilux model 501 represented the high intensity halogen type; the Apollo95E typified the plasma arc technology; and AccuCure was used as an argon laser system. Testing consisted of bonding 360 stainless steel adhesive pre-coated lower central brackets (APC, 3M Unitek) to bovine teeth. The bond strength was tested at the two-minute, ten-minute, one-hour, two-day, one-week, and one-month post polymerization time points. Curing times were consistent with respective manufacturer's recommendation: 40 seconds for the Demetron, 20 seconds for the Optilux, 6 seconds for the Apollo95E, and 10 seconds for the AccuCur. The one-month specimens were subjected to 1440 cycles of thermal cycling between 5°C and 55°C.

Statistical analyses included a two-way ANOVA, Student-Neuman-Keuls Multiple Comparison Tests, and paired t-tests. These tests showed that there was no statistically significant difference in bond strength for any of the specimens that were cured with these lights (α=0.05), except for those cured with the laser light which exhibited significantly weaker bond strength (p<0.0001). The paired t-tests showed that there was no statistically significant difference in bond strength between the one-month samples, which included the thermal cycling effect, and the one-week samples (α=0.05) for each of the lights, with the exception of the laser light. Among the laser light test groups, the one-month samples, which include the thermal cycle effect, exhibited significantly weaker bond strength when compared with the one-week samples (p=0.0001).

LLU Discipline

Orthodontics and Dentofacial Orthopedics

Department

Dentistry

School

Graduate School

First Advisor

Willis L. Schlenker

Second Advisor

Joseph M. Caruso

Third Advisor

Daniel A. Flores

Fourth Advisor

Jay A. Kim

Fifth Advisor

Carlos A. Munoz

Degree Name

Master of Science (MS)

Degree Level

M.S.

Year Degree Awarded

2000

Date (Title Page)

6-2000

Language

English

Library of Congress/MESH Subject Headings

Orthodontic Brackets; Dental Bonding

Type

Thesis

Page Count

viii; 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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