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.
Joseph M. Caruso
Daniel A. Flores
David R. Rynearson
Michael J. Fillman
M. Toufic Jeiroudi
Willis L. Schlenker
Master of Science (MS)
Year Degree Awarded
Date (Title Page)
Library of Congress/MESH Subject Headings
Cementation -- methods; Dental Cements -- analysis; Light; Materials Testing -- methods
Loma Linda University Libraries
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.
Unruh, Perry M., "A Shear Bondstrength Evaluation of Five Orthodontic Light-Cured Adhesives" (1992). Loma Linda University Electronic Theses, Dissertations & Projects. 1862.
Loma Linda University Electronic Theses and Dissertations
Loma Linda University. Del E. Webb Memorial Library. University Archives