Color- and strength-graded zirconia: Strength, light transmission, and composition
Anvita Maharishi1, Edward A McLaren2, Shane N White3
1Assistant Professor, Department of Family Dentistry, College of Dentistry, University of Iowa, Iowa City, Iowa, USA.
The Journal of Prosthetic Dentistry
|March 30, 2024
Summary
Graded zirconia blocks offer improved strength and translucency for dental restorations. A new color- and strength-graded zirconia demonstrated superior biaxial flexural strength and light transmission compared to color-graded blocks.
Area of Science:
- Dental Materials Science
- Biomaterials Engineering
- Ceramic Engineering
Background:
- Natural teeth exhibit natural gradients in translucency and strength.
- Graded zirconia materials aim to mimic these natural gradients by varying yttria content.
- These graded materials may reduce the need for porcelain veneering in dental crowns.
Purpose of the Study:
- To compare biaxial flexural strength, light transmission, elemental, and phase content of graded zirconia blocks.
- To evaluate color-graded and color- and strength-graded zirconia materials.
- To assess the zonal properties of advanced zirconia materials for dental applications.
Main Methods:
- Fabrication of color-graded and color- and strength-graded zirconia blocks.
- Measurement of biaxial flexural strength using a piston-on-3-ball test.
- Quantification of light transmission, elemental composition (X-ray fluorescence), and phase content (XRD) in different zones.
Main Results:
- The color- and strength-graded zirconia showed significant gradients in strength, light transmission, elemental, and phase composition across its zones.
- The dentin zone of the strength-graded material exhibited substantially higher strength than all other zones.
- Both materials demonstrated high light transmissibility in their enamel zones, with significant differences observed between the two materials overall and in specific zones.
Conclusions:
- A zirconia material graded for both color and strength offers significant advantages for dental restorations.
- These graded materials provide a promising alternative to traditional uniform zirconia, potentially enhancing aesthetics and mechanical properties.
- Further research into the clinical performance of these advanced graded zirconia materials is warranted.
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