Color Changes of Ceramic Materials Used for Inlay and Veneers Restorations after Staining with Different Time Intervals

Background: Stain color of CAD/CAM prosthetic materials is important for the long-term of these materials without affecting daily beverage consumption habits.

Aims: To assess the influence of aging with Coca-Cola drinks on the color of the CAD/CAM materials used for inlay and veneer restoration over different time intervals.

Methods: 48 specimens were fabricated from Vitablocs Mark II and zirconia CAD/CAM ceramic materials. Each group comprised 24 specimens with eight samples for every background (white [W], black [B], and gray). Baseline readings were taken by a spectrophotometer before staining (Baseline T0). After Coca-Cola staining and aging, the color measurement was repeated after 15 and 30 days (T1 and T2), while T3 was the difference between T2-T0. The data were analyzed with descriptive statistics, one-way ANOVA, and post hoc tests.

Results: The ΔE00 color parameters of Mark II and zirconia materials were higher against the W background than other backgrounds. However, the zirconia materials recorded higher values than Mark II for the same parameters (L, a, and b) against the gray background during 15 and 30 days of immersion in Coca-Cola. Translucency parameters (TP) exhibited significant differences between ceramic types and immersion periods, with the TP values of zirconia being slightly higher than those of Mark II. The ΔE00 values for the three-time intervals were within clinically acceptable ranges. The ΔE00 values of both ceramic types at T3 were within 1.38–1.53 and 3.11–3.62 and lacked significant differences.

Conclusions: Coca-Cola staining was obvious after 15 and 30 days of immersion and had a marked effect on the TP and ΔE00 of the tested CAD/CAM materials. Increasing the staining time resulted in a reduction in TP values at all time intervals. Zirconia samples had higher ΔE00 values than Mark II materials at different time periods. All of the colors of the tested materials had changed from B1 to different light colors in accordance with the Vita classical shade guide.