Reconditioning of ceramic orthodontic brackets with an Er,Cr:YSGG laser
2012, DOI: 10.1007/s10103-012-1093-4
Abstract
It
is now known that erbium lasers are effective in composite removal, but
there is minimal information about their efficacy
on recycling of ceramic brackets. This study, therefore,
aimed to determine the percentage of remaining adhesive on the base
and the shear bond strength of debonded ceramic brackets
after being reconditioned by an Er,Cr:YSGG (erbium, chromium:
yttrium–scandium–gallium–garnet)
laser. Thirty premolars were divided into three groups, then
bonded with mechanical retention ceramic brackets according to
the bracket base conditions: (1) new brackets; (2) debonded
brackets cleaned of adhesive with the Er,Cr:YSGG laser at 3.5 W;
and (3) debonded brackets cleaned of adhesive with the
Er,Cr:YSGG laser at 4 W. Before bonding, the percentage of remaining
adhesive on the bases of reconditioned brackets was
calculated by using stereomicroscopic images through an image processing
software. The brackets were then tested in shear mode in a
universal testing machine and the adhesive remnant index scores
were determined. The percentage of remaining adhesive on the
bases of brackets that were cleaned by the Er,Cr:YSGG laser at
4 W (3.1 %) was significantly lower than that of the 3.5-W
laser group (5.9 %) (p = 0.03). No significant difference was found in bond strengths between the new and the reconditioned brackets (p
= 0.19). The frequency of bond failure at the enamel-adhesive interface
was lower in the laser-reconditioned brackets when
compared to the new brackets. The application of Er,Cr:YSGG
laser was efficient in removing adhesive from bases of debonded
ceramic brackets because it produced comparable bond
strengths to new brackets while reducing the risk of enamel damage
during
debonding.
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