Changes in bracket slot tolerance following recycling of direct-bond metallic orthodontic appliances.

Stainless steel direct-bond orthodontic brackets manufactured by three different companies were evaluated for changes in ability to be torqued by a rectangular arch wire after being recycled by three commercially available methods. Through two successive recycles, no clinically significant changes in the fit of the arch wire to engage the bracket were found for any of the three different methods. Greater experimental values of bracket tolerance or fit in degrees for wire twist, compared to theoretical calculations by previous investigators, were attributed to beveled edges found on the rectangular arch wires.