Oral Health Care Zone for Grown-upss - Oral Treatments - Crown

A crown refers to the placement of an artificial crown on a tooth. It acts as a 'cap' that fits over the tooth which mimics a real crown of tooth

Purpose

To restore the original shape and function of teeth. To improve the esthetics 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. To protect teeth from fracture. Tooth that has undergone root canal therapy and with a large filling is more brittle. It can be protected from fracture when a crown is placed.

Materials

Porcelain Metal alloy Properties Durable High wear resistance Metal alloy crown can be quite thin --- only a small amount of tooth substance needs to be removed to accommodate it Disadvantage Metallic colour, poor esthetics Application Used at high stress bearing area where good esthetics is not a must. For example, posterior teeth Procedures for metal alloy crown Remove a thin layer of tooth substance on all surfaces of the crown. Take impressions of the upper and lower teeth and record the bite. Construct a temporary crown to protect the prepared tooth. Fabricate the metal alloy crown in the dental laboratory. Remove the temporary crown and clean the tooth surface. Cement the crown onto the tooth. Porcelain fused to metal Properties Esthetic --- colour of outer surface is similar to natural tooth Strong and durable because of the metal alloy base Hard Disadvantage: Relatively 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 metal crown A thin layer of the tooth is removed Take impressions of the upper and lower teeth and record the bite. Construct a temporary crown to protect the prepared tooth. Fabricate the porcelain fused to metal crown in the dental laboratory. Remove the temporary crown and clean the tooth surface. Cement the crown onto the tooth. Stainless steel Properties Stainless steel crown is not custom-made. It is preformed into certain sizes. Since the crown is not custom-made, the procedures of fitting are simple and the time taken is relatively short. Disadvantages Silvery colour, unesthetic Non-stress bearing, not lasting Causes tooth decay and gum disease easily --- since the crown margin is not closely adapted to the tooth, the margin is prone to accumulation of dental plaque Application Used on molars of deciduous teeth As temporary crown before the permanent crown is ready for use Procedures for stainless steel crown Remove a thin layer of the tooth surface structure. Choose the right size stainless steel crown and try it in the tooth. Trim the crown according to the contour of the tooth. Clean the tooth surface. Cement the crown onto the tooth.