Metal brackets were recycled by variable methods for economic reason. Such recycling methods had a great effect on bracket slot width and bonding strength. Therefore, the recycling methods that don´t change the properties of original bracket were suggested.
In this study, debonded brackets were recycled with 30 kinds of solvents and bracket surfaces were examined by S.E.M. (Super IIIA, ISI International Scientific Instruments, Japan) and Stero Microscope (Sz-Tr, Olympus Tokyo, Japan) methods.
The following results were obtained.
l. Thermosetting resin adhesives (eq. Monolok®, Concise®) were swelled most in sulfuric acid (assays 95%) and slightly in:alcohol groups. S
2. The solvent was exchanged every 24 hours during the brackets were recycled with sulfuric acid (assays 95%)_ As the passage of time, the adhesives were removed more clearly, and after 72 hours adhesives were nearly detached from bracket baes.
3. Chemical recycled metal bracket surface showed no irregular structure by S E.M. method.
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