Abstract
Objectives: This investigation was carried out to examine the influence of thermocycling aging on the surface roughness (Ra, mm), color parameters (L*, a*, b*), lightness change (DL*), chroma change (DC*ab), color change (DE), and microhardness (VH) of three lithium disilicate ceramics.Materials and methods: Forty-five specimens were prepared from three lithium disilicate materials (n = 15)-e.max CAD (EC), e.max Press (EP), and GC Initial LiSi Press (LP) ceramics-with dimensions of 6.0 x 1.2 x 16.0 +/- 0.2 mm following the manufacturers' instructions. All specimens were exposed to 5000 thermal cycles with bath temperatures ranging between 5 degrees C and 55 degrees C. Data of surface roughness, color parameters, and microhardness were obtained using an optical profiler, a spectrophotometer, and a Vickers hardness tester, respectively. One-way ANOVA, a post-hoc Tukey's test, and a paired sample t-test were implemented for statistical analysis (p <= 0.05).Results: For surface roughness, insignificant differences were reported between the materials either before or after thermocycling (p > 0.05) while each material displayed a significant increase after being subjected to thermocycling (p < 0.05). For color parameters, LP showed significantly lower L* and b* after thermocycling while EC presented a significant reduction in a* in comparison with other materials (p < 0.05). EP showed a significant decrease in AL*, AC*ab and AE compared with other materials (p < 0.05). Regarding microhardness, LP showed significantly increase value in comparison with other materials (p < 0.05).Conclusions: Thermocycling had a major impact on the surface roughness, microhardness and optical characteristics of the tested materials. E.max Press displayed less changes in (AL*), (AC*ab) and (AE), while GC LiSi Press had better behavior in terms of microhardness.(c) 2022 The Authors. Production and hosting by Elsevier B.V. on behalf of King Saud University. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).