Fracture Resistance of Occlusal Rests in CAD/CAM All-Ceramic Survey Crowns
Abstract
Metal-ceramic survey crowns have been the gold standard for integrating fixed and removable prosthodontics due to their advantageous mechanical properties and esthetics. Improvements in CAD/CAM technology and the enhanced physical properties of monolithic ceramics make all-ceramic restoratives a viable alternative to metal ceramic survey crowns in supporting clasp-type removable partial dentures (RPD). The objective of this study was to compare failure loads at the occlusal rests of zirconia and lithium disilicate survey crowns before and after one year simulated aging. Virtual premolar survey crowns were designed with CAD software (Exocad) incorporating the manufacturers recommended minimum thickness requirements for zirconia (IPS e.maxZirCAD LT) and lithium disilicate (IPS e.max CAD). The survey crown preparation designs had adequate reduction for an occlusal RPD rest. Monolithic zirconia (n=16) and lithium disilicate (n=16) survey crowns were milled using a 5-axis milling machine. Individual dies were directly fabricated by injecting composite resin (3M Filtek Universal Restorative) into the lubricated crown intaglio. The crowns were then cemented to the dies using a resin cement (Ivoclar Multilink Automix) following the manufacturer's instructions.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 25, 2021
- Accession Number
- AD1182977
Entities
People
- Krystal H. Burns
Organizations
- Uniformed Services University of the Health Sciences