Porcelain Refinishing with Two Different Polishing Systems after Orthodontic Debonding

Abstract

To compare the effects of two polishing systems on the surface roughness of three types of porcelain after orthodontic debonding. A total of 90 porcelain discs were fabricated from feldspathic (n = 30), leucite-based (n = 30) or lithia disilicate-based (n = 30) ceramics. Ten samples in each group served as the control and received no surface treatment. The remaining 60 samples in three of the porcelain groups were bonded with lower incisor brackets and debonded using a testing machine in shear mode at a rate of 1 mm/minute crosshead speed. After debonding, the remaining adhesive resin was removed with a tungsten carbide bur. Then, two experimental subgroups (10 each) in each porcelain group were treated as follows: in the first subgroup, porcelain polishing wheel and polishing paste were applied, whereas in the second, polishing was performed using a series of Sof-Lex discs. The average surface roughness (Ra) of the all samples was evaluated using SPM/AFM (surface probe microscope/atomic force microscope). Data were statistically analyzed by analysis of variance for each porcelain material and polishing method. The polishing techniques affected surface roughness significantly. There were significant differences between the groups; higher Ra values were obtained with the use of porcelain polishing wheel and polishing paste (P < .001). The application of Sof-Lex discs can produce smoother porcelain surfaces than porcelain polishing wheel and polishing paste.