ALL CERAMIC CROWNS
These are crowns made purely from porcelain or ceramic and no other material like, porcelain fused to metal or only metal like gold etc. These crowns are highly esthetic as the material of these crowns, allows the light to pass through them .It does not absorb the light like metal does, so they are lifelike and translucent , blending with the rest of the teeth.
These crowns are of superior quality and last many years.
Most of the, “all ceramic metal free crowns” are fabricated, using the CAD/CAM technology ie Computer aided designed and computer aided manufactured. Thus the fit is very precise .
There are two types of ceramic crowns,
ADVANTAGES OF ALL CERAMIC CROWNS
These crowns are chosen by people, who value quality and a life like natural appearance of their crowns and also those who have minimal space in their mouths. These crowns are light as they are free from any heavy metal. Plus the margins with the gum are flush, as they being biocompatible allow the gum to grow alongside the crown. These crowns cause no allergic reactions and also do not cause any sensitivity to hot or cold foods.
DISADVANTAGES OF ALL CERAMIC CROWNS
These crowns are prone to chipping or cracking or breaking as they are less durable than other types of crowns. They are technique sensitive and require high degree of expertise for fabrication. This increases the cost.
HOW ARE ALL-CERAMIC CROWNS FITTED?
The procedure for fitting an all ceramic crown is the same as any other crown. It requires two sittings. In the first sitting the dentist will clean and shape the tooth , to create space for the crown material. The logic is the tooth and the crown together should be the size of a normal tooth.
An impression of the prepared tooth is made with putty and wash and sent to the laboratory. Since the fabrication of the crown will take a week or two, a temporary crown is given for the interim period.
In the second sitting the dentist will remove the temporary crown and temporary cement and check the fit of the crown. Once he is satisfied the crown is fixed with a dental cement.
A zirconia crown is durable and esthetic and made of a strong crystal. Thus it has a wide usage in the medical field and is used for replacing joints eg knee etc.
It is usually recommended for the back or posterior teeth. It is life like as the light passes through it. The preparation of the tooth is minimal, so more of the natural tooth material is conserved. This is an advantage if for some reason the crown needs to be removed later.
The tough durable material of Zirconia has the disadvantage of wearing off the opposing natural tooth, because it is slightly abrasive.
The Emax crown is preferred for its esrhetics and is recommended for the front / anterior teeth. So these crowns are used for smile makeovers and cover stained, damaged, chipped teeth. It has an appealing translucent colour which blends with the enamel translucency.
A single block of lithium disilicate ceramic is used to fabricate this crown.This material is known to be durable and strong. Yet the crown has a delicate lifelike appearance. This emax crown is the best match for the natural teeth. The cost is a factor to be considered , though anyone valuing quality and esthetics would be ready to pay the premium. The other big advantage is that since there is no metal alloy base the ugly grey line at the margin of the crown and gum is not an issue .