Evaluation of translucency, color stability, and surface roughness of advanced lithium silicate ceramics before and after thermocycling

Objective To compare the color stability, translucency, and surface roughness of different advanced lithium disilicates (ALDS) before and after coffee thermocycling. Materials and methods Twenty-one rectangular-shaped disk were prepared from three different lithium silicate-based materials (CEREC Tessera, Initial Lisi, Amber Mill) (n = 7) for each group. All specimens were finished and polished. Color coordinates were measured with a spectrophotometer, and surface roughness by an optical profilometer. All specimens were then aged with 5000 cycles of coffee thermocycling were done to all samples and measurements were repeated. The color difference (∆E00), relative translucency parameter (RTP), and roughness average (Ra) were calculated. Statistical analysis was performed using mixed model two-way ANOVA followed by Tukey’s post hoc test. Results Both tested variables (material type (p < 0.001) and coffee thermocycling(p < 0.001)) had a significant effect on translucency, while for surface roughness (Ra) both material type (p = 0.471) and coffee thermocycling (p = 0.282) had no significant effect. CEREC Tessera had the least ∆E00 = 1.8 followed by Initial Lisi = 2.24 followed by Amber mill = 3.1 Conclusion The translucency of tested materials increases by coffee thermocycling, but surface roughness is unaffected. Amber Mill has the highest translucency among the tested groups and Cerec Tessera is a promising material regarding color stability.