Esthetic appearances of anatomic contour zirconia crowns made by additive wet deposition and subtractive dry milling: A self-controlled clinical trial

Anatomic contour zirconia crowns are widely used in clinical dental practice because of their mechanical reliability and improved appearance. However, few studies have performed clinical evaluations of the esthetics of these crowns in terms of color and translucency gradient. The purpose of this clinical trial was to compare the esthetic effect and color-matching behaviors of anatomic contour zirconia crowns manufactured with 3-dimensional (3D) gel deposition and dry milling methods. Twenty-seven premolar teeth of 27 participants received 2 identical anatomic contour zirconia crowns fabricated by additive 3D gel deposition or dry milling. Color differences (ΔE) between the crown and natural control teeth were measured by a dental shade-matching device. Subjective color matching was rated by professionals using an extended visual rating scale for appearance match (EVRSAM) and by participants using a visual analog scale (VAS). Data were analyzed by using repeated measures ANOVA, the Bonferroni test, paired Student t test, Pearson chi-square test, and Wilcoxon test (α=.05). Significant differences were found in ΔE between zirconia crown and core types (P.05). The average ΔE of crowns made by wet deposition and dry milling were 2.45 ±1.60 and 4.55 ±1.54 (P