Base-Coated Zirconia Brackets for Orthodontics

Yttria and iron co-doped tetragonal zirconia polycrystals ((Y, Fe)-TZPs) were investigated to evaluate the feasibility for the ceramic bracket application. Presintered the (Y,Fe)-TZPs brackets were machined, abraded and coated with granule spray containing 10~50 wt% of flux. Finally, the base-coated brackets were sintered. Roughness of the coated surface was decreased to 13 um and 10 um when the flux content was 30 wt% and 50 wt%, respectively. It may be due to the fusion and the collapse of the granules as a result of the high amount of flux. Better adhesion to the base surface of the brackets and irregular shape were observed by raising the amount of flux in the slurries. Wetting angle of ethylene glycol droplet on the (Y,Fe)-TZP bare surface was determined to be 41.85°, however, the angle became 0° after the granule spraying treatments. The (Y,Fe)-TZP brackets exhibited uniform embossed base and good wetting. The newly developed base-coated bracket could be highly applicable to enhance retention and to reduce adhesive resin remnant during the bracket debonding.