IADR Abstract Archives
New Advanced Lithium Disilicate Ceramic – Development and Technical Insights
Abstract Body: A new high strength glass ceramic with zirconia and virgilite crystals is presented. Discussion focuses on microstructure and the material's mechanical, chemical and fatigue test data. The resulting excellent machinability via CAD/CAM grinding and esthetics make the material perfect for high-end full-anatomical ceramic crowns. The high strength glass-ceramic is an integral part of a faster firing work-flow when combined with a high-speed dental furnace.
Fracture strength of the new high strength glass ceramics is above 700 MPa (biaxial). Wear of the material is in the range of human enamel. A CTE of 9,8 x10-6 K-1 allows the material to be veneered as cut-back / correction with current veneering ceramics, if so desired.
Two main types of crystal structures are embedded in an amorphous (glass) matrix: Lithium Disilicate crystals with a mean size of approx. 600nm and Virgilit with a mean size of approx. 200nm. Both crystal types are the source of an opalescence effect and together with oxides for pigmentation result in a natural tooth look.
The material shows excellent marginal stability, allowing a reduction of wall thickness to min. 1,0 mm (adhesive) and min. 1,5 mm (glass ionomer) during CAD/CAM grinding. The minimum wall thickness for veneers is 0,4 - 0,6 mm.
Dental restorations made from this new high strength glass ceramics require only a short glaze firing: When using a high-speed dental furnace the firing cycle time takes – even with stains – only 4,5 minutes.
This new high-strength glass-ceramic is available under the tradename Cerec Tessera by Dentsply Sirona.
Fracture strength of the new high strength glass ceramics is above 700 MPa (biaxial). Wear of the material is in the range of human enamel. A CTE of 9,8 x10-6 K-1 allows the material to be veneered as cut-back / correction with current veneering ceramics, if so desired.
Two main types of crystal structures are embedded in an amorphous (glass) matrix: Lithium Disilicate crystals with a mean size of approx. 600nm and Virgilit with a mean size of approx. 200nm. Both crystal types are the source of an opalescence effect and together with oxides for pigmentation result in a natural tooth look.
The material shows excellent marginal stability, allowing a reduction of wall thickness to min. 1,0 mm (adhesive) and min. 1,5 mm (glass ionomer) during CAD/CAM grinding. The minimum wall thickness for veneers is 0,4 - 0,6 mm.
Dental restorations made from this new high strength glass ceramics require only a short glaze firing: When using a high-speed dental furnace the firing cycle time takes – even with stains – only 4,5 minutes.
This new high-strength glass-ceramic is available under the tradename Cerec Tessera by Dentsply Sirona.