Influence of Arabic Qahwa Beverage on Optical and Mechanical Properties of Lithium Disilicate Glass Ceramics and Zirconia Restorative Materials.

Aims: The study aims to assess the effect of Arabic Qahwa (AQ) on the color parameters of lithium disilicate glass ceramic (LDGC), IPS e.max computer-aided design (CAD), and multilayered zirconia CAD/ computer-aided manufacturing (CAM) ceramic materials after immersion in AQ and also, to measure the biaxial fracture strength and fracture modes of the tested materials.

Materials And Methods: Sixty circular specimens were milled from LDGC and zirconia. Before AQ immersion, the color parameters of the specimens L, a, and b were measured and recorded using a spectrophotometer on white, black, and gray background and analyzed after AQ staining and aging for 14 days. Biaxial compressive forces and fracture types were recorded. The collected data were analyzed with SPSS for descriptive statistics, one-way analysis of variance, and tests.

Results: The overall TP values were 16.79 and 15.85 for LDGC and zirconia, respectively. The recorded Δ* values were 2.63 and 2.99 for LDGC and zirconia, which have no remarkable difference. The TP values after AQ staining were slightly lesser. Subgroup analysis revealed considerable differences in TP values among zirconia specimens under both backgrounds, whereas substantial differences in Δ* values were observed between LDGC and zirconia under white background only. Lithium disilicate glass ceramic (LDGC) had higher biaxial fracture forces than zirconia. Reparable, semi-reparable, and non-reparable fractures comprised 60, 30, and 10% of the overall fracture modes, respectively, with significant differences between and within groups ( = 0.034).

Conclusion: AQ staining had a marked effect on the TP and Δ* values of the tested CAD/CAM materials, but the values were within clinically acceptable levels. The optical properties were dependent on the material. Lithium disilicate glass ceramic (LDGC) had higher biaxial fracture forces than zirconia. Reparable fracture was the dominant type among the examined materials.

Clinical Significance: Glazed surface for any CAD/CAM ceramic prostheses is highly recommended. Both tested materials are strongly recommended to be used for AQ consumers.