Surface, Colorimetric, and Optical Properties of New-Generation Lithium Disilicate Ceramics.

Area of Science:

• Dental Materials Science
• Biomaterials Engineering
• Ceramic Engineering

Background:

• Lithium disilicate-based glass-ceramics (LDC) are crucial for esthetic dental restorations.
• Their surface and optical properties are influenced by composition and surface treatments.
• Understanding these variations is key to optimizing restoration outcomes.

Purpose of the Study:

• To compare surface, colorimetric, and optical properties of different LDC compositions.
• To evaluate the effects of polishing versus glazing surface treatments on LDC materials.
• To provide insights into material selection and treatment for esthetic dental restorations.

Main Methods:

• Four LDC CAD/CAM block compositions were prepared and divided into polishing and glazing subgroups.
• Baseline and post-treatment measurements included surface roughness (Ra), color, translucency (TP), contrast ratio (CR), opalescence (OP), and gloss (GU).
• Statistical analysis (Mann-Whitney U, Kruskal-Wallis H, Wilcoxon signed-rank tests) was performed (α = 0.05).

Main Results:

• Both glazing and polishing significantly reduced surface roughness (Ra) across all LDC materials.
• Glazing resulted in higher gloss (GU) and lower opalescence (OP) compared to polishing.
• Glazing led to greater color change (ΔE00) for IPS e.max CAD and Initial LiSi, and increased translucency for IPS e.max CAD.

Conclusions:

• LDC material composition and surface treatment significantly impact surface, colorimetric, and optical properties.
• Glazing is more effective than polishing in enhancing surface gloss and reducing roughness.
• Glazing induces material-specific color shifts and can enhance translucency, particularly for IPS e.max CAD.