Differences in Applications of Glass Ceramics and Zirconia

Glass ceramics and zirconia are two commonly used materials in dental restorations. They each have their own advantages and disadvantages and are suitable for different clinical scenarios.

1. Mechanical properties
Glass ceramics:
Strength: about 120-500 MPa (depending on the type, such as lithium disilicate is stronger).
Toughness: low, prone to brittle fracture.
Wear resistance: good, but not as good as zirconium oxide.
Zirconia:
Strength: about 900-1200 MPa, much higher than glass ceramics.
Toughness: high, excellent fracture resistance.
Wear resistance: excellent, close to natural enamel.

2.Aesthetic properties
Glass ceramics:
Transparency: high, very close to natural enamel, suitable for anterior restorations.
Color: can be highly personalized by staining or glazing.
Zirconia:
Transparency: low, especially traditional zirconium oxide (high-transparency zirconium oxide has been improved).
Color: usually requires veneer porcelain or staining to improve the aesthetic effect.

3.Clinical applications
Glass ceramics:
Anterior veneers, inlays, onlays, single crowns.
Suitable for restorations with high aesthetic requirements.
Zirconia:
Posterior single crowns, long bridges, implant superstructures.
Suitable for restorations with high strength requirements.

Glass ceramics are more suitable for aesthetic restorations of anterior teeth, while zirconium oxide is more suitable for high-strength restorations of posterior teeth.