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Marginal Fit Comparison of CAD/CAM Crowns Milled from Two Different Materials.
Atousa Azarbal1, Mohsen Azarbal1, Robert L Engelmeier1
1Department of Prosthodontics, University of Pittsburgh School of Dental Medicine, Pittsburgh, PA.
Summary
CAD/CAM crowns made from hybrid ceramic show better marginal fit than those made from lithium disilicate. Crystallization firing significantly increases the marginal gap in lithium disilicate crowns.
Area of Science:
- Dental Materials Science
- Biomaterials Engineering
- Prosthodontics
Background:
- Accurate marginal fit of dental restorations is crucial for long-term success.
- CAD/CAM technology offers precise fabrication of dental prosthetics.
- Evaluating new ceramic materials for CAD/CAM restorations is essential.
Purpose of the Study:
- To compare the marginal fit of CAD/CAM copings fabricated from hybrid ceramic (Vita Enamic) and lithium disilicate (IPS e.max CAD).
- To assess the impact of crystallization firing on the marginal fit of lithium disilicate copings.
Main Methods:
- Standardized metal dies were used to fabricate 15 hybrid ceramic and 15 lithium disilicate copings via CAD/CAM.
- Copings were seated under uniform pressure, and marginal gaps were measured using microscopy and image analysis.
- Marginal gap measurements for lithium disilicate copings were taken before and after crystallization firing.
Main Results:
- Hybrid ceramic copings exhibited a statistically significant better marginal fit compared to crystallized lithium disilicate copings.
- Crystallization firing of lithium disilicate copings resulted in a significant increase in the mean marginal gap (average 62 μm).
Conclusions:
- There is a significant difference in marginal gap discrepancy between hybrid ceramic and lithium disilicate CAD/CAM crowns.
- Crystallization firing negatively impacts the marginal fit of lithium disilicate CAD/CAM restorations.
