Effect of Glazing Protocol on the Surface Roughness and Optical Properties of Lithia-Based Glass-Ceramics

Background: New lithia-based glass–ceramics, including Advanced Lithium Disilicate (ALD), have become popular in dentistry. However, it is unclear if glazing protocols for ALD might compromise its surface or optical properties. Thus, evaluating color and translucency changes in ALD and traditional lithium disilicate (LD) is crucial. Methods: This study aimed to assess how different firing protocols affect the surface and optical properties of LD and ALD. Sixty disc-shaped specimens were prepared, divided into three subgroups based on firing protocols, and subjected to surface roughness analysis. Specimens were immersed in coffee, wine, and water for 7 days, and then brushed. Color and translucency were measured. Results: Firing protocols significantly influenced surface roughness in LD (0.09–1.39 µm) and ALD (0.05–0.88 µm). Color differences were observed in both LD and ALD after 7 days, with visible changes within clinically acceptable thresholds. Translucency remained stable across firing protocols and staining liquids. Conclusions: Varying firing protocols impact surface roughness and color stability in LD and ALD. Despite differences, color and translucency changes remained within acceptable clinical thresholds, suggesting both materials are suitable for dental applications. Therefore, this study reinforces the reliability and versatility of these materials in restorative dentistry.