Do Polishing Methods and Colorant Beverages Affect the Color Stainability of 3D-printed Permanent Restorations?

Abstract

Aim: This in vitro study evaluated the effect of polishing methods on the color stainability of 3D-printed permanent restorations while immersed in colorant beverages (distilled water, tea, coffee, and red wine) for 30 days. Materials and Methods: A total of 120-disc-shaped samples (10 mm × 1.5 mm) were fabricated using a stereolithography printer (Formlabs 3B, Formlabs, Massachusetts) with a three-dimensional (3D)-printable permanent resin (Permanent Crown, Formlabs, Massachusetts). The samples were polished with mechanical polishing, Optiglaze (GC Dental Products Corp, Aichi, Japan), or Vita Akzent LC (VITA Zahnfabrik, Bad Säckingen, Germany) (n = 40). Initial color measurements were performed using a spectrophotometer (VITA Easyshade V; Vita Zahnfabrik). Then the samples were divided into four different subgroups depending on beverages immersed in distilled water, coffee, tea, and red wine (n = 10). After immersion in beverages for 30 days, color measurements were repeated. Color changes were calculated using the CIEDE2000 color change (ΔE00) formula. ΔE00 was evaluated according to 50:50% color perceptibility (PT00 = 0.81) and acceptability (AT00 = 1.81) thresholds. A two-way analysis of variance (ANOVA), Tukey HSD test with Bonferroni adjustment, and paired-sample t-tests were used for statistical evaluation. Results: The highest ΔE00 was noted in mechanical polishing groups (p