Color Stability of Three Ceramics After Thermocycling in Coffee, Black Tea, Cola, and Water: An In Vitro Study

Background: Ceramic restorations have become a cornerstone of modern dentistry. Color stability is crucial for dental ceramics to maintain the esthetic appearance of restorations over time. Objectives: Given the widespread consumption of staining agents like coffee, tea, and cola, this study aimed to assess the color stability of three ceramics after thermocycling in different solutions. Materials and Methods: In this in vitro study, 120 samples of Vita Suprinity PC, IPS e.max, and InCoris ZI (40 samples each) were prepared as disks with 1 mm thickness and 10 mm diameter in A2 shade and glazed per manufacturer guidelines. The 10 samples of each group underwent 5000 thermocycles in coffee, black tea, cola, or tap water (5 and 55°C) with a dwell time of 30 s and a transfer time of 10 s simulating approximately 6 months of clinical use. To assess color change, ΔE was calculated using a calibrated spectrophotometer (X Rite, sp60 series, USA). L (for the lightness/darkness), a (for redness/greenness), and b (for yellowness/blueness) were measured before and after immersing. The data were analyzed using ANOVA with SPSS version 26.0. at the significance level of 0.05. Results: According to the results in all three groups, ∆E was significantly higher in the coffee subgroup compared to the black tea, cola, and water subgroups; was significantly higher in the black tea subgroup compared to the cola and water subgroups; and was significantly higher in the cola subgroup than the water subgroup (p  < 0.001). In the comparison of all four solutions, the color change in the Vita Suprinity PC samples was more significant compared to IPS e.max and InCoris ZI samples; and was more significant in IPS e.max than InCoris ZI (p  < 0.001). ∆E values for Vita Suprinity PC and IPS e.max were perceptible (∆E > 1) but clinically acceptable (∆E < 3.7), while InCoris ZI's ∆E was imperceptible (∆E < 1). Conclusion: The color stability of monolithic zirconia was more than lithium disilicate in coffee, black tea, cola, and water solutions. The color of lithium disilicate was more stable than zirconia-reinforced lithium silicate in all staining solutions. Coffee, black tea, and cola consumption can affect ceramic restorations' color change. Coffee has a more staining effect among different beverages.