Recycling the Orthodontic Bonded Bracket

Abstract

This investigation was designed to determine the effects of recycling orthodontic bonded attachments in the Esmadent bracket and band reconditioner. The machine contains an oven for bonding resin burnoff, and an electropolishing bath for tarnish removal. It was hypothesized that electropolishing removed sufficient surface metal from the attachment to significantly affect its integrity and function. The parameters selected for evaluation were slot width, mesh dimension, attachment weight, and the resistance of the bracket wings to compressive stress. Medium twin, 0.018 in. slot brackets, welded to mesh bonding pads, were recycled according to the manufacturer's recommendations with the following results. 1. After 2 cycles, the slot width had increased by 0.0005 in., and by 3 cycles, the slot width was greater than 0.019 in. 2. Photographic assessment of the mesh backing showed an increase in pore size, with increasing numbers of cycles. 3. Attachment weight and resistance of the bracket wings to compressive stress decreased with increasing numbers of cycles. The causative agent was determined to be the electropolishing cycle. From a clinical standpoint, change in bracket slot width appears to be the limiting factor. Only one, or possibly two cycles may be tolerated before the ability of the wire to move the bracket, and thus the tooth, is compromised.