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For highly aesthetic restorations
High strength glass-ceramics are used in particular for highly aesthetic restorations. The aesthetic finishing requires special know-how and time. However, in order to cement them in the posterior with a conservative preparation design and, if necessary, conventional manner, the material strength is a particular factor for the safety and durability of these restorations. Seamless workflows in the dental laboratory and the dental practice can offer an additional advantage.
High strength glass ceramics from Dentsply Sirona
Complementary veneering system
Benefits
Why choose our high strength glass ceramics?
Innovative materials
Excellent aesthetics
Strength to rely on
Fast and easy processing
Strength to rely on
CEREC Tessera and Celtra Press offer outstanding mechanical properties for digital and traditional workflows. Learn more about their mechanical properties below.
CEREC Tessera
The trifecta of speed, strength, and aesthetics in the dental laboratory
CEREC Tessera blocks achieve exceptional three-way performance through a unique chemistry that incorporates two complementary crystal structures within a glassy zirconia matrix. These two crystals work together to create an unprecedented fusion of strength and beauty in one block while significantly improving overall processing time.
Lithium disilicate
Rod-shaped crystals provide strength in the same manner as rebar embedded in cement. These crystals increase the density of the material while helping protect against crack propagation.
Virgilite
Used in glass ceramics, these crystals are unique to CEREC Tessera material. They are activated through the matrix firing process and add strength while contributing to the outstanding aesthetics that give the convincing appearance of natural teeth.
Mechanical properties
- Up to 32% higher strength than competition2
- High biaxial flexural strength of >700 MPa
- Allows conservative preparations design, with reduced risk of margin chipping
- The unique combination of crystal structures and glass adds further assurance due to surface healing while firing
- With adhesive cementation you can achieve a 1.0 mm wall thickness
Microstructure of CEREC Tessera: 2 crystal types create a densely packed, crystallisation strengthened glass ceramic: Lithium disilicate (in purple): "Rod" crystals, approx. 600 nm; Virgilite (in pink): "Round" crystals, approx. 200 nm
Celtra Press
The ultra-fine microstructure makes all the difference
The outstanding properties of ZLS (zirconia-reinforced lithium silicate) are a function of its unique microstructure. The presence of 10% zirconia in the glass phase in atomically dissolved form provides high strength and ensures safe and long-lasting restorations. The zirconia is essentially responsible for the nucleation of crystal phase.
The result is a large number of very fine-grained lithium silicate, whose high glass content give the material its excellent light-optical and mechanical properties. Translucency, opalescence, fluorescence, and the chameleon effect all benefit, with high edge stability and excellent polishability being an added plus. This ultra-fine microstructure allows Celtra to be processed quickly and efficiently in a dental laboratory in its crystalline state and in the appropriate tooth shade.
Mechnical Properties
- Multiphase ceramic consisting of a glass matrix and lithium disilicate crystals
- Crystal length of about 1.5 µm plus nano-scale lithium phosphate
- Contains about 10% zirconia (ZrO2), which is dissolved completely in the glass phase rather than in crystalline form
- High biaxial flexural strength of >600 MPa (after power firing)3
- Excellent flow properties during pressing
Unpressed Ingot: Celtra Press ingot MT A2 with etched surface (Lithium Silicate crystal ~ 0.5 μm) compared to a Conventional LS₂ Press ingot HT A2 with etched surface (Lithium Disilicate crystal ~ 1.8 μm). Smaller crystal length in pellet results in easier flow during pressing of the restoration.
Pressed Material: Celtra Press ingot MT A2 with etched surface (Lithium Silicate crystal ~ 1.4 μm, Lithium Phosphate ~ 0.3 μm) compared to a Conventional LS₂ ingot HT A2 with etched surface (Lithium Disilicate crystal ~ 4.2 μm). Smaller crystals leads to easier polishing.
