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If tooth damage due to
caries or other causes is so extensive that an inlay or onlay is no longer an
option for stability reasons, but the tooth root is still intact, then a dental
prosthesis in the form of a crown is required. A dental achievement that has
proven itself in recent years to be the ideal material for high-quality dental
prostheses is the all-ceramic crown made of zirconium. The "white
gold"- also called ceramic steel- is a dental prosthesis that meets the
highest demands.
What kind of material is
zircon (abbreviation for zirconium dioxide/zirconium oxide/zirconium dioxide)?
Zirconium dioxide is made
from zirconium silicate. This silicate sand is washed, cleaned and calcined to
obtain a 99 percent pure zirconium dioxide powder. This powder is sintered
(heated under high pressure) to produce highly resilient ceramics. The material
is characterised by high abrasion resistance and good chemical resistance.
Zirconium oxide is used, among other things, as a prosthetic material - for hip
joint implants, for example - or in dentistry for the production of
tooth-coloured crowns, bridges and implants that should not contain metal. For
telescopic dentures, primary telescopes can be made of zirconium oxide.
What types of zircon
crowns are available?
The fully veneered zirconia
crown (veneer crown) consists of a milled zirconia framework that is
veneered with ceramic in layers by hand by the dental technician. The natural
tooth colour is exactly reproduced in the process. The HT zirconia crown (HT =
High Translucent) is milled monolithically from a block of zirconia, whereby
the zirconia block is selected in advance according to the matching shade.
After the HT zirconia crown has been fabricated, only the patient's individual
tooth colour is applied and fired.
What are the advantages
of zirconia crowns for the patient?
Zircon crowns are very
hard and resistant. Crowns made of this material have a high bending strength
and can withstand a strong chewing load, therefore they are very durable. An
all-ceramic crown does not need a metal framework, so even if the gums recede,
no dark crown margin will be visible on the gums. Zircon crowns are
colour-stable and hypoallergenic, and the very smooth surface of the material
is difficult for plaque to adhere to. Due to its basic colour characteristics
and the light transmission similar to natural teeth, zirconium matches your own
teeth aesthetically perfectly and can be matched very precisely to the
individual tooth colour with ceramic veneering or colouring.
What are the
disadvantages of zirconia crowns?
For the fabrication of a
zircon crown, from the preparation and colour determination to the fitting of
the finished crown in the denture, 3-4 sessions at the dentist are required.
For notorious teeth grinders, ceramic dentures may be unsuitable due to their
brittle hardness. With veneered ceramic crowns, chipping of small pieces of
veneer may occur, the so-called "chipping".