Color Stability and Surface Roughness of Two Restorative Material–Production Systems: Effects of Surface Finishing and Brushing with Two Commercial Toothpastes with Different RDA Classifications

Background/Objectives: This in vitro study compared color and roughness changes after simulated toothbrushing in milled GC Cerasmart 270 (CS) and 3D-printed Formlabs Permanent Crown (FL) following glazing or mechanical polishing. Methods: Eighty specimens were assigned to eight groups (2 × 2 × 2 factorial design; n = 10) using Colgate Total or Colgate Whitening (Colgate-Palmolive Co., Guangzhou, China). Published relative dentin abrasivity (RDA) values were 70 and 124, respectively; RDA was not measured in this study. Color coordinates and mean surface roughness (Ra) were measured before and after 10,000 brushing cycles. CIEDE2000 color differences (ΔE00) and Ra were analyzed using three-way factorial analysis of variance (ANOVA) and mixed repeated-measures ANOVA, respectively. Results: The material–production system × finishing interaction was significant for ΔE00 (p = 0.035; partial η2 = 0.060). Mechanically polished FL showed greater color change than mechanically polished CS (mean difference: 0.56; Tukey-adjusted 95% confidence interval (CI): 0.13–0.99). Ra increased after brushing (p < 0.001; partial η2 = 0.846), with a material–production system × finishing × time interaction (p = 0.002; partial η2 = 0.127). Among mechanically polished specimens, FL showed a greater Ra increase than CS (mean difference in change: 0.025 µm; Tukey-adjusted 95% CI: 0.006–0.045 µm). No significant toothpaste main effect was detected for either outcome. Conclusions: Mechanically polished FL showed greater color change and Ra increase than mechanically polished CS. Mean color differences remained below the acceptability threshold, although some individual specimens exceeded it. Each manufacturing approach and toothpaste condition was represented by one commercial product, preventing separation of manufacturing-method and RDA effects from formulation.