Effect of surface finishing and polishing procedures on color properties and translucency of monolithic zirconia restorations at varying thickness

Objective This study aimed to assess the impact of monolithic zirconia thickness on its color properties after different surface finishing and polishing procedures, and following aging in coffee solution. Materials and methods Two types of monolithic zirconia brands [Prettau Anterior (PA) and DD Cubex2 (DDC)] with three different thicknesses: 0.5, 1, and 1.5, and 10 mm diameter were tested. The color properties were evaluated after various surface finishing procedures (glazing, adjusting with burs + glaze, polishing, adjusting with burs + polishing) and after 5,000 cycles in a coffee solution were evaluated. The differences in color (Delta E) and translucency, were calculated and statistically analyzed by three-way ANOVA and pairwise comparison (alpha = 0.05). Results The brand, material thickness, and surface finishing protocol before and after coffee thermocycling had significant effect on color variations (p < 0.001). For translucency, 3-way ANOVA revealed a significant interaction between the material thickness and surface finishing protocol following aging in coffee solution (p < 0.001), however no significant interaction was observed following the surface finishing protocols (p = 0.247). Conclusions The optical properties of monolithic zirconia ceramics can be influenced by the material brand, material thickness and the procedure of surface finishing and polishing. Clinical significance Clinicians should take into consideration the potential change of the color properties of monolithic zirconia restorations following both contouring and occlusal adjustment procedures and coffee intake.

Automated summary

The study demonstrated that the color properties of monolithic zirconia are influenced by the material brand, thickness, and surface finishing and polishing procedures. These factors have a significant impact on the optical properties of the material during aging.