الفهرس 
he introduction of acid etch technique in 1955 by Buonocore
Experimental study design was adopted in this study.Only 14 pages are availabe for public view
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Abstract
one proplem that clinicians face during treatment is the bracket
failure. This is usually the consequence of a patient accidently
applying inappropriate force to the bracket or a poor bonding
technique. Thus, a significant number of teeth must be rebonded in a busy
orthodontic practice. One solution is to recycle the brackets.
Bracket recycling can be performed either in the dental office or by
specialized companies. However, because of time consuming process of
commercial recycling, in-office recycling is preferred option. The in-office
recycling method employed in this study was the Er:YAG laser.
The purpose of the present study was to evaluate the effects of
recycling and repeated recycling with Er:YAG laser on shear bond strength
and surface characteristics of stainless steel orthodontic brackets.
This study was carried on ninety human upper first premolars extracted
as a part of orthodontic treatment. The teeth were randomly divided into 3
groups; one control and two experimental groups of 30/ each.
group I (control group): Thirty new brackets were bonded to upper first
premolars and subdivided into:
•Twenty brackets for shear bond strength testing.
•Ten brackets debonded for scanning electron microscope to identify
the surface characteristics of the bracket mesh.
group II: Thirty debonded brackets were recycled one time with Er:YAG
laser and subdivided into:
•Twenty recycled brackets were rebonded to upper first premolars as
with initial bonding and subjected to shear bond strength testing.