Effect of two polishing systems on color and surface roughness of feldspathic porcelain following orthodontic bracket debonding and composite resin removal

Objectives: Orthodontic bracket removal from a porcelain crown can roughen the surface and lead to plaque accumulation, discoloration, and esthetic problems. Porcelain polishing after debonding is one strategy to decrease such consequences. This study aimed to compare the efficacy of two polishing systems (Sof-Lex discs and Meisinger polishing system) for correction of surface roughness and discoloration of porcelain after orthodontic bracket debonding. Materials and Methods: Twenty porcelain blocks were evaluated in two groups of 10. First, the baseline surface roughness and color parameters of the samples were measured using atomic force microscopy and spectrophotometry, respectively. After bracket bonding, a fine cutter was used for bracket debonding, and resin remnants were removed by a tungsten carbide bur and low-speed handpiece. Samples were then polished using Sof-Lex discs (group 1) and Meisinger porcelain polishing kit (group 2). Surface roughness and color parameters were measured again. Data were analyzed using SPSS 18 through the Shapiro-Wilk test, Student's t-test, and paired t-test at 5% level of significance. Results: Porcelain color change (AE) was significantly greater in the Meisinger system than Sof-Lex (P < 0.001). The Rq, Ra, and Rt surface roughness parameters significantly increased in both the groups after the intervention compared to baseline (P < 0.05), but the two groups were not significantly different in this respect after the polishing procedures (P> 0.05). Conclusion: The porcelain color after polishing with Sof-Lex discs was closer to the baseline. Furthermore, the two systems were not significantly different regarding surface roughness. However, Sof-Lex discs may be recommended due to lower cost.