When a tooth breaks, chips or decays in a way that compromises the strength of that tooth, a crown is often the best way to save and strengthen it. They are often associated with root-canalled teeth, where the nerve and blood supply of the tooth has been removed. A crown is a fabricated “cap” used to sit over and cover the remaining natural tooth. The crown is used to replace the portion of the tooth that sits above the gum-line.
A bridge is used to replace one or more missing teeth. The bridge is an artificial tooth which is fixed to the natural teeth on either side of the gap with partial crowns.
Types of crowns and bridges
There are a few common materials used for the fabrication of a crown and bridge. These include:
- Gold alloy crowns
- Porcelain fused to metal crowns (PFM-metal is usually a gold alloy)
- All porcelain crowns
- Zirconia-based crowns – Zirconia is a hard white-coloured material. It is very good when an excellent aesthetic finish is required for the bridge or crown restoration.
All materials listed above are well tolerated by the cheek and gums. The type of material used for the restoration of damaged teeth will depend on its position in the mouth, and also on the patient’s preference. As a general rule, crowns or bridges that use gold alloy are used for teeth located towards the back of the mouth.
Crowns and Bridges are used, not just for cosmetic reasons, but for: restoring tooth function (e.g. restoring chewing), preventing shifting teeth and excessive stress to surrounding teeth.
There are generally 3 stages to a Crown/Bridge procedure:
- First Stage: Examination (including possible x-rays) and primary impressions to get models of the teeth.
- Second Stage: Preparing the tooth for the Crown/Bridge. This includes:
- Building up the core/centre of the tooth or teeth.
- Cutting the tooth or teeth down to the correct shape and size.
- Taking a secondary impression of the prepared teeth.
- Taking a correct shade match and placing a temporary restoration on top of the prepared tooth/teeth.
- Third Stage: This stage involves removing the temporary crown/bridge and cementing the permanent restoration on to the tooth/teeth. Some minor adjustment of the bite may be necessary. It is always best to consult us if you feel that a crown is necessary. If we feel that a tooth may be too difficult for a general dentist to restore, we can organise a referral to a prosthodontist who deals in the restoration of teeth and bites.