Dental ceramics and zirconia
- Dental material
Ceramics give crowns a natural look. Glassy ceramics look best and are bonded on; zirconia is the strongest and suits back teeth and bridges.
What it is
Dental ceramics range from very glassy, translucent porcelains to dense polycrystalline zirconia. The more glass a ceramic has, the more natural it looks and the more it relies on bonding to the tooth for strength; the more crystalline, the stronger and more opaque it is. Many are now milled from blocks with CAD/CAM.
Composition and properties
- Feldspathic porcelain: the most lifelike, but brittle; used for veneers and as a layer over metal or zirconia.
- Glass-ceramics (such as lithium disilicate): strong and aesthetic; etched with hydrofluoric acid, primed with silane and bonded with resin cement.
- Zirconia: the strongest; cannot be etched, so it is air-abraded and bonded with a phosphate-monomer primer or cemented conventionally.
- Metal–ceramic crowns: a metal coping under porcelain, long track record.
- Ceramics are brittle: they fail by chipping or fracture rather than bending.
Uses, limits and safety
- Layered porcelain over zirconia can chip; full-contour (monolithic) zirconia chips far less.
- Rough or unglazed ceramic wears the opposing teeth quickly; polished or glazed surfaces are kinder.
- Hydrofluoric acid is highly toxic and corrosive: it is used only on the restoration, outside the mouth, with protection.
Next step / Initial management
- Front teeth and veneers: glass-ceramics bonded with resin cement; back teeth and bridges under heavy bite or bruxism: zirconia.
- Chipped or cracked ceramic crown: keep the pieces and refer to the dentist; small chips may be repaired.
- Skin or eye contact with hydrofluoric acid: wash at once and seek urgent medical care.
Test yourself
Think of the answer, then tap the question to see it.
How is a lithium disilicate crown prepared for bonding?
It is etched with hydrofluoric acid, treated with a silane primer and bonded with resin cement.
Why is zirconia not etched with hydrofluoric acid?
It has no glass phase for the acid to dissolve, so it is air-abraded and primed instead.
What is the main way ceramic crowns fail?
By chipping or fracture, because ceramics are brittle.
Connections
Educational content; it does not replace assessment by a dentist or doctor and is not a clinical instruction. For facial or neck swelling with difficulty swallowing or breathing, a knocked-out tooth or bleeding that will not stop, go to an emergency department at once.
Sources: Zirconia Biomaterials (StatPearls Publishing (NCBI Bookshelf), 2023); Glass-Ceramics in Dentistry: A Review (Materials (Basel) (PMC open access), 2020); Ceramics for Dental Applications: A Review (Materials (PMC open access), 2010).
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Representative model, for educational purposes only.