A crown refers to the placement of an artificial crown on a tooth. It acts as a 'cap' that fits over the tooth which has been previously shaped and contoured.
Purpose
To restore the original shape and function of teeth
To improve the aesthetics of teeth, such as shape, size and colour
To fix a bridge onto the teeth — a fixed bridge is supported by crowns on either / both side
Gold alloy crown can be quite thin — only a small amount of tooth substance needs to be removed to accommodate it
Disadvantage
Metallic colour, poor aesthetics
Application
Used
at high stress bearing area where good aesthetics is
not a must. For example, posterior teeth
Procedures for gold alloy crown
A thin layer of tooth substance on all surfaces of the crown is removed.
Impressions of the upper and lower teeth are taken and the bite registration is recorded. The prepared tooth is protected by a temporary crown.
The gold alloy crown is fabricated in the dental laboratory.
Temporary crown is removed and the tooth surface is cleaned.
The crown is cemented onto the tooth.
Porcelain
fused to gold
Properties
Aesthetic — colour of outer surface is similar to natural tooth
Strong and durable because of the gold alloy base
Hard
Disadvantage:
More tooth substance needs to be removed from the facial surface of the tooth.
Application：
Used
on anterior teeth
Before treatment
After treatment
Procedures for porcelain fused to gold crown
A thin layer of the tooth is removed.
Impressions of the upper and lower teeth are taken and the bite registration is recorded. The prepared tooth is protected by a temporary crown.
The porcelain fused to gold crown is fabricated in the dental laboratory.
The temporary crown is removed and the tooth surface is cleaned.
The crown is cemented onto the tooth.
Stainless steel
Properties
Stainless steel crown is not custom-made. It is preformed with several sizes.
Since the crown is not custom-made, the procedures of fitting are simple and the time taken is relatively short.
Disadvantage
Silvery colour, unaesthetic
Non-stress bearing, not lasting
Since the crown margin is not closely adapted to the tooth, the margin is prone to accumulation of dental plaque which causes dental caries and periodontal disease
Application
Used on molars of deciduous teeth
Procedures for stainless steel crown
A thin layer of the tooth is removed.
The stainless steel crown with the right size that fits the tooth most is chosen.
The crown is then trimmed according to the contour of the tooth.
