Related Experiment Video
Updated: Sep 8, 2025
Quasistatic Mechanical Testing for Computer-Aided Design and Manufacturing Occlusal Veneers Cemented to Milled Dentin Analog Material
Published on: December 20, 2024
Comparative evaluation of optical properties of lithium disilicate crowns fabricated by pressable and CAD CAM methods
Shweta A Gaikwad1, Amit K Jagtap1, V N V Madhav1
1Department of Prosthodontics, Crown & Bridge and Implantology, Dr. D. Y. Patil Dental College and Hospital, Dr. D. Y. Patil Vidyapeeth, Pimpri, Pune, 411018, India.
Aim:
The aim of this study was to compare the optical performance of pressable and milled lithium disilicate crowns, focusing on their shade-matching accuracy against the VITA Classical A1 shade guide.
Material And Methods:
20 samples each of lithium disilicate crowns were fabricated using pressable and CAD/CAM-milled techniques and VITA A1 shade tab as the control. A spectrophotometer was used to measure the optical properties of the crown, namely, brightness (L∗), red-green (a∗), blue-yellow (b∗), and color difference (ΔE) values. Data obtained was analyzed statistically to assess shade-matching precision and optical differences.
Results:
The lightness (L∗) value of the pressable group (92.22 ± 2.67) was significantly higher than that of the milled group (88.10 ± 1.08) and the control group (87.78 ± 0.08). Regarding the red-green axis (a∗), the pressable group had the highest mean value (0.97 ± 0.37), followed by milled (0.85 ± 0.24) and control (0.35 ± 0.11), showed statistically significant differences. In terms of yellow-blue chroma (b), the pressable crowns recorded the highest value (14.89 ± 0.99), followed by the control (14.43 ± 0.07) and milled (13.56 ± 0.25). Milled crowns exhibited a significantly lower ΔE (1.49 ± 0.42) compared to pressable crowns (4.71 ± 2.55).
Conclusion:
Milled lithium disilicate crowns showed superior shade-matching accuracy, which exhibited lower color difference (ΔE) values, inferring closer color alignment with the A1 standard. Pressable crowns showed enhanced translucency and esthetic vibrancy as contributed by higher brightness and chromatic intensity, but exhibited greater variability in color matching.
