Dental crowns are prosthesis that surrounds and wraps the tooth all around to protect it against fracture. It is usually done for root canal treated tooth or badly decayed tooth with compromised structure.
What are the types of crown?
There are generally 4 types of dental crowns categorized based on the material:
1. Full metal crown
2. Porcelain fused metal crown
3. Zirconia crown
4. Porcelain crown
Full Metal Crown
Full metal crowns are entirely silver-coloured crowns on the inside as well as surface of the crown.
Due to its colour, these are usually used in the back areas of the mouth
eg. Upper molars, occasionally lower molars
These crowns are best suited for vital tooth that has not gone through root canal treatment
as it is very thin and require only a small amount of tooth reduction which preserves the tooth structure and maintains vitality of tooth.
Porcelain fused metal crown
Porcelain fused metal crowns are tooth-coloured crowns with inner metal lining.
It is the most widely used crown due to its affordability and cost effectiveness. Due to the metal lining, it can produce a slight greyish tint on surface of the tooth. As a result, it is best suited for all back teeth as well as on front teeth in less esthetically demanding cases.
The layered porcelain may wear or chip off after some time, exposing the metal surface.
It does not affect functionality of the crown, however, it can be very obvious and affect the esthetics especially on front teeth. It might also wear out opposing tooth over the years if bite force is high or grinding is present.
Zirconia crowns are tooth-coloured crowns. They are the most durable among the types of crowns. These crowns are highly resistant to chipping and breaking and are therefore suitable for those who grinds their teeth at night. These crowns can be used for front teeth as well as molars.
One of the advantages of Zirconia crowns is that, though it is strong and durable, it does not wear off opposing teeth like porcelain.
Zirconia crowns tend to be more opaque in colour and therefore requires some layering with porcelain if to be used on front teeth for better esthetic outcome.
Zirconia crowns doesn’t chip. However, there are chances of chipping off porcelain from the zirconia crown but is highly unlikely. Zirconia layered crowns are indicated for those with severe discolouration on their front teeth that cannot be masked with a porcelain crown.
Porcelain crowns are tooth-coloured crowns.
They offer the best esthetics and are suitable for those looking for the most natural looking crowns.
These crowns are resistant to stains and are translucent which mimics the natural tooth.
That being said, due to the lack of support of a metal or zirconia core, porcelain crowns are more susceptible to chipping and breakage. Though brittle, its hardness is more than the natural tooth and can therefore cause the opposing tooth to be worn out after some time.
Porcelain crowns are usually indicated on the front teeth that has lesser biting force and more esthetic demanding.