Effect of different implant abutment materials on optical properties of translucent monolithic zirconia crowns

The use of translucent monolithic zirconia crowns in implant dentistry raises concerns about the underlying abutment color affecting esthetic outcomes. While abutment effects are documented for traditional ceramics, data are limited for modern monolithic zirconia. The purpose of this investigation is to evaluate how abutment material and zirconia brand influence the final color of translucent monolithic zirconia crowns.

Eighty monolithic zirconia crowns (four brands; n = 20 each) were fabricated in shade A2 and cemented onto five abutment types: titanium (Ti), gold-hued Ti, pink-hued Ti, zirconia, and a natural dentin-shaded control. Crowns were placed on abutments using opaque try-in paste, and color was measured using a spectrophotometer. ∆E00 values were calculated and analyzed using two-way ANOVA and Tukey post hoc testing (α = 0.05).

Both abutment material and zirconia brand significantly influenced ∆E00 values (p < 0.001), with a significant interaction effect between the two variables. Zirconia abutments yielded the lowest color difference (∆E00 = 0.77), below the perceptibility threshold. Katana Zirconia HT exhibited the least color change across abutments. All metallic abutments produced ∆E00 values categorized as moderately unacceptable, with the highest values observed for pink-hued titanium.

Color outcomes of translucent monolithic zirconia crowns are strongly influenced by the abutment material and zirconia brand. Zirconia abutments help minimize color deviation, while metallic abutments-especially pink Ti-may produce clinically perceptible shade changes.