Influence of Composition and Thickness on The Color and Translucency of Glass-Ceramic Materials for Laminate Veneer Restorations: An In Vitro study

Abstract

Statement of the problem: Numerous glass-ceramic materials are com-mercially available, yet achieving optimal esthetic results relies significantly on material composition and thickness. The selection of suitable material and thickness poses an ongoing challenge in clinical practice. Objective: This study aimed to investigate the effect of the composition and thickness of different glass-ceramic materials on the Commission Interna-tionale de l'éclairage (CIE) L*, a*, and b* color coordinates and the translucency parameter (TP00). Materials & Methods: Glass-ceramic blocks of A2 shade, with low translucency, encompassing feldspathic (FS), leucite-reinforced feldspathic (LR), and lithium-disilicate (LD) compositions, were sectioned into three thick-nesses: 0.5 mm, 0.7 mm, and 1 mm (n=10). All specimens were polished with ceramic polishing rubbers. Using a spectrophotometer, the CIE L*, a*, and b* color coordinates of the specimens were measured over gray, white, and black backgrounds. The TP00 was calculated using the CIEDE2000 color difference for-mula. The CIE L*, a*, b*, and TP00 were analyzed using two-way ANOVA and Tukey HSD post-hoc tests (?=0.05). Results: Material, thickness, and their interaction significantly influ-enced the CIE L*, a*, b*, and TP00 values (P<0.001). The LR group displayed the highest L* and a* values, while the LD group showed the lowest (P<0.001). Con-versely, the LD group exhibited the highest b* value (P<0.001). Lightness was lowest in 0.5 mm-thick specimens (P<0.001) and similar for 0.7 mm-thick and 1.0 mm-thick specimens (P>0.05). Redness and yellowness increased with in-creasing thickness (P<0.001). Regardless of thickness, the FS group had the high-est TP00 (16.32±1.54), while the LR group had the lowest TP00 (14.31±1.67). Re-gardless of material, 0.5 mm-thick specimens demonstrated significantly higher TP00 (17.49±1.10) than 0.7 mm-thick (15.45±0.83) and 1.0 mm-thick (13.11±1.12) specimens. There was no significant difference between the 0.5 mm-thick FS and LD groups (P>0.05) and 1.0 mm-thick LR and LD groups (P>0.05).