A crown covers a tooth to improve its appearance or restore its function if it has become broken down, has a very large filling or is
- Metal(inside) bonded to porcelain(outside)
- All ceramic
- Composite resin
Gold Crowns are probably the best in terms of function and durability but appearance is obviously an issue and cannot be considered at the front of the mouth.
The 3 other types are tooth coloured with the new ceramic crowns being the best esthetically (particularly their appearance at the gum).
The tooth to be crowned must first be prepared under local anaesthetic and then impressions of the preparation of the prepared tooth and opposing teeth taken . A temporary crown is usually cemented at the end of this visit and the impressions sent to a dental laboratory where the crown is fabricated. Usually about 2 weeks later the temporary crown is removed and the new crown is cemented into place.
Complex crown and bridge cases sometimes require diagnostic study casts and wax ups of the proposed crowns/bridges for the dentist and patient to assess how everything will look at the end of treatment.
The images shown illustrate the difference in appearance between the highly esthetic all ceramic crowns, which have a very life-like appearance and are difficult to distinguish from normal teeth, and the composite resin crowns (shown in the bottom picture), which although improving the appearance considerably, are not as life-like. Please note that these are 2 separate cases.