Knowledge

Dental Zirconia Ceramic Block for Prosthodontics

General information
Dental Zirconia Ceramic Block for Prosthodontics is a high-performance ceramic material with zirconia (ZrO₂) as its main ingredient, which is widely used in restorative dentistry for the fabrication of all-ceramic crowns, bridges, veneers, implant superstructures, and other prosthetic restorations. With its excellent mechanical properties, biocompatibility, and aesthetic effect, it has become one of the mainstream materials for modern dental restorations.

Development history
1970s: Zirconia was first studied as a biomaterial and attracted attention for its high strength and corrosion resistance.
1990s: With the breakthrough of ceramic processing technology (e.g., CAD/CAM), zirconia ceramic blocks began to be used in dental restorations.
Early 21st century: By adding stabilizers (e.g., yttrium oxide), highly translucent zirconia materials were developed, dramatically improving aesthetic properties.
Since then, zirconia blocks have become the core material for all-ceramic restorations and have been continuously optimized to meet diverse clinical needs.

Material properties
Physical and chemical properties

High strength: Flexural strength up to 900-1200 MPa, far beyond traditional glass ceramics.
Excellent toughness: the phase change toughening mechanism significantly reduces the risk of brittle fracture.
Wear-resistant: hardness close to natural tooth enamel, not easy to wear in long-term use.
Chemical stability: acid and alkali corrosion resistance, no release of harmful ions.
Biocompatibility

No cytotoxicity, excellent compatibility with human tissue, suitable for long-term implantation.
Hypoallergenic, reducing the risk of patient allergy.
Aesthetic performance

Light transmission close to natural teeth can be multi-layer stained or veneered porcelain modification to achieve personalized aesthetic restoration.
Processing performance

CAD/CAM (computer-aided design and manufacturing) technology can be used to accurately cut and adapt to complex dental morphology.

Production process
Raw material preparation
High-purity zirconia powder is mixed with stabilizers (e.g., 3Y-TZP with 3% yttrium oxide) and sintered at high temperatures to form pre-formed blocks.
CAD/CAM Processing
The patient's dental data is obtained through oral scanning, the restoration is designed by computer, and the porcelain is cut by CNC machine to form the block.
Sintering
After preliminary processing, the porcelain blocks are sintered at high temperature (1350-1500℃) and densified to enhance strength and light transmission.
Surface treatment
Dyeing, glazing, or stacking the surface of the porcelain to enhance the aesthetic effect.

Clinical applications
Single-unit restorations: full zirconia crowns, inlays, and high inlays.
Multi-unit restorations: zirconia bridges (up to 4-6 units supported).
Implant restorations: implant-supported zirconia abutments and upper crowns.
Aesthetic restorations: anterior veneers, full zirconia veneer crowns.
Advantages and limitations
Advantages:
High strength, suitable for posterior and long-span restorations;
Excellent biocompatibility; no risk of metal sensitization;
Aesthetically realistic, high marginal closure.
Limitations:
Higher cost of highly translucent zirconia;
High requirements for mechanic processing equipment;
Microcracks or chipping may occur in rare cases.

Common brands
International brands:
Ivoclar IPS e.max ZirCAD
Dentsply Sirona inCoris TZI
3M Lava™ Plus

National Brands:
Eltron (Upcera)
Mega
Huge

Precautions
Clinical Indications: Porcelain blocks of appropriate strength need to be selected according to the patient's occlusal situation and the degree of dental defects.
Processing accuracy: CAD/CAM equipment needs to be calibrated regularly to avoid cutting errors.
Bonding treatment: The zirconia surface needs to be sandblasted or coated (e.g., silica coating) to improve bonding strength.
Long-term maintenance: Patients should have regular checkups and avoid biting hard objects to prolong the life of the restorations.

References
Prosthodontics (People's Health Publishing House)
ISO 13356:2016 Standard for Zirconia Ceramic Materials for Dental Purposes
Related academic papers and manufacturers' technical manuals