Orthodontic molar brackets: the effect of three different base designs on shear bond strength
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Date
2011
Journal Title
Journal ISSN
Volume Title
Publisher
Master Publishing Group
Abstract
The purpose of the study was to assess the relative base designs of three different maxillary molar stainless
steel brackets with reference to the shear bond strength of three different adhesive resins. The molar
brackets used were Victory series (3M Unitek), Upper Molar (GAC) and Optimesh XRT (Ormco). The adhesives
used were Transbond XT (3M Unitek), Enlight (Ormco) and Sure Ortho Light Bond (Sure Orthodontics).
The human enamel specimens (144) were randomly divided into nine groups and each group (n=16) was
allocated to a bracket/adhesive combination. The contact surface of each of the bracket bases was measured
three dimensionally using a reflex microscope. The base designs were also subjected to further microscopic
investigations. The brackets were bonded to the enamel, temperature cycled and the shear bond strength
was measured. The size and design of each of the brackets was different. The base size, surface treatment,
mesh strand diameter and aperture size of the bracket base mesh have a significant effect on the shear
bond strength at the bracket/adhesive interface. The shear bond strengths of all three Ormco bracket/adhesive
resin combinations (5.8-6.8 MPa) were significantly lower (p<0.05; Kruskal-Wallis) than the other six
bracket/adhesive combinations (9.4-12.1 MPa). The different adhesive types (3 types) could not be mainly
responsible for the low shear bond values found for the Ormco bracket. The 3M Unitek combination of
the Victory series bracket and Transbond XT adhesive proved to have a high shear bond strength without
enamel damage.
Description
Keywords
Base design, Molars, Shear bond strength, Stainless steel brackets
Citation
Hudson, A.P.G., Grobler, S.R. & Harris, A.M.P. (2011). The effect of base design on shear bond strength of three different stainless steel orthodontic molar brackets. International Journal of Biomedical Sciences, 7(1): 27-34