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Published on: December 20, 2024
Biomechanical behavior of endodontically treated premolars using different preparation designs and CAD/CAM materials
Diogo Pedrollo Lise1, Annelies Van Ende2, Jan De Munck2
1KU Leuven (University of Leuven), Department of Oral Health Sciences, BIOMAT & University Hospitals Leuven (UZ Leuven), Dentistry, Leuven, Belgium; Federal University of Santa Catarina (UFSC), Department of Operative Dentistry, Florianópolis, SC, Brazil.
For endodontically treated premolars without ferrule, a 2.5-mm deep endocrown made of composite showed higher load-to-failure than lithium disilicate. Shallow endocrowns benefit from more flexible composite materials.
Area of Science:
- Dental materials science
- Restorative dentistry
- Biomaterials engineering
Background:
- Endodontically treated teeth require restoration to regain function and strength.
- CAD/CAM (Computer-Aided Design/Computer-Aided Manufacturing) offers precise fabrication of dental restorations.
- The ferrule effect is crucial for post-and-core and crown retention, but its absence poses a challenge for restoration stability.
Purpose of the Study:
- To compare the load-to-failure of endodontically treated premolars restored with different endocrown designs and CAD/CAM materials without a ferrule.
- To investigate the influence of restoration depth (2.5-mm vs. 5-mm) and material type (composite vs. lithium disilicate) on fracture resistance.
Main Methods:
- Forty-eight endodontically treated premolars were restored with either 2.5-mm or 5-mm deep endocrowns or 5-mm deep post-and-crowns using composite or lithium disilicate.
- Restorations were fabricated using CAD/CAM technology and cemented with luting composite.
- Teeth underwent cyclic loading simulating chewing, followed by a compressive load test to determine load-to-failure and failure modes.
Main Results:
- All specimens withstood 1.2 million chewing cycles.
- A significant interaction was observed between restoration design and material type.
- Composite endocrowns with a 2.5-mm depth exhibited higher load-to-failure compared to lithium disilicate, while no material difference was noted for 5-mm deep endocrowns or post-and-crowns.
Conclusions:
- In shallow 2.5-mm endocrown preparations, composite demonstrates superior load-to-failure compared to lithium disilicate, potentially due to differences in elastic modulus.
- The choice of a more flexible composite material is advantageous for shallow endocrown restorations lacking a ferrule.
- Restoration design and material selection are critical factors influencing the mechanical stability of endodontically treated premolars.
