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Published on: December 20, 2024
In vitro failure of crowns produced by two CAD/CAM systems
Thomas J Donnelly1, F J Trevor Burke
1Primary Dental Care Research Group, University of Birmingham, School of Dentistry, College of Medical and Dental Sciences, UK.
Summary
This study compared the fracture resistance of Lava (zirconia-based) and Cerec (feldspathic porcelain) dental crowns. Lava crowns demonstrated significantly higher fracture resistance than Cerec crowns when bonded with a self-adhesive resin cement.
Area of Science:
- Dental Materials Science
- Biomaterials Engineering
- Restorative Dentistry
Background:
- All-ceramic crowns are widely used in restorative dentistry.
- Previous studies show good fracture resistance with resin-composite luting agents and dentine bonding systems.
- CAD/CAM technology offers precise fabrication of ceramic restorations.
Purpose of the Study:
- To compare the compressive fracture resistance of teeth restored with CAD/CAM fabricated Lava (zirconia-based) and Cerec (feldspathic porcelain) crowns.
- To evaluate the failure modes of these restored teeth.
- To assess the efficacy of a self-adhesive resin luting material in bonding these ceramic crowns.
Main Methods:
- Standardized preparations were made on maxillary premolar teeth.
- Two groups of ceramic crowns (Lava and Cerec) with 2mm thickness were fabricated using CAD/CAM.
- Compressive fracture resistance was measured using a Universal Testing Machine, and failure modes were analyzed.
Main Results:
- Mean compressive fracture resistance was 746 (147)N for Cerec crowns and 1630 (175)N for Lava crowns.
- The difference in fracture resistance between the two groups was statistically significant (p < 0.001).
- Lava crowns exhibited significantly greater fracture resistance compared to Cerec crowns.
Conclusions:
- Teeth restored with Lava (zirconia-based) crowns exhibit significantly higher fracture resistance than those restored with Cerec (feldspathic porcelain) crowns.
- The self-adhesive resin luting material (RelyX Unicem Clicker 3M ESPE) was used for both crown types.
- These findings have implications for material selection in CAD/CAM dental restorations.
