A crown is a restoration designed to restore the shape, and colour of a cracked, worn, discoloured, mis-shaped, or heavily filled tooth. A crown usually covers the entire surface of the tooth. The procedure involves multiple steps, ending with it cemented onto the prepared tooth.
The purpose of a crown may be to:
A crown requires removal of tooth structure which is irreversible. Depending of what is needed, it may not be appropriate for your tooth. Talk to your Prosthodontist to see if it is a suitable option.
A crown may not be the first choice for :
Alternatives to a crown may include, a filling or an onlay. An onlay provides similar function to a crown, but retains more tooth structure.
Following initial consultation and diagnosis, tooth structure is removed from all surfaces to create space for the crown. This is done very precisely. After the preparation is complete, an impression (mould) or digital scan (optical impression) is taken. The shade (colour) is chosen, and a temporary crown fitted until the definitive crown is returned from the laboratory. Fabrication of the crown usually takes between one and four weeks. At the second appointment, your temporary crown is removed, and the fit and appearance of the new crown assessed. It is then cemented on the tooth. More visits required, especially if multiple crowns are prescribed.
Crowns are highly predictable, with over 90% surviving over 10 years. Risks and Complications include:
Following initial consultation and diagnosis, tooth structure is removed from all surfaces to create space for the crown. This is done very precisely. After the preparation is complete, an impression (mould) or digital scan (optical impression) is taken. The shade (colour) is chosen, and a temporary crown fitted until the definitive crown is returned from the laboratory. Fabrication of the crown usually takes between one and four weeks. At the second appointment, your temporary crown is removed, and the fit and appearance of the new crown assessed. It is then cemented on the tooth. More visits required, especially if multiple crowns are prescribed.
Crowns can be made from a number of materials. Your Prosthodontist will discuss which is the appropriate for your situation. ‘Traditional’ materials are metal, or porcelain-fused-to-metal. Other materials, such as ceramic (Lithium disilicate) and Zirconia are also frequently prescribed. Chipping or breaking of the tooth-coloured material (e.g. porcelain) is always a risk.
Your Prosthodontist may indicate additional treatment prior to crown preparation is necessary.
The health of the gum (periodontium) is extremely important. Inflamed and bleeding gums may be a problem during a crown procedure. Additionally, if left untreated, gum disease can lead to loss of the supporting bone, exposing the crown edge and possibly mobility and loss of the tooth;
A foundation restoration is used (where necessary) to rebuild large parts of the tooth before the crown. Conventional direct filling materials (amalgam or composite resin) may be used. A post and core can be necessary if there is too little tooth remaining for preparation;
Root canal treatment (endodontics) is not required before crowning a healthy tooth. Some cases may require a root filling, when:
A small percentage of teeth which do not require a root canal treatment before a crown may require one after it is placed.
The cost of a crown can vary depending on difficulty. While it is not always the case, a prosthodontist may charge more than a general dentist. The cost of other associated treatment (such as root canal treatment, gum treatment, etc.) should also be discussed prior to proceeding with any procedure.
A dental crown is a tooth shaped “cap” that covers the entire surface of a tooth. If a tooth has suffered extensive decay, tooth wear, fracture or is more filling than tooth, a crown may be the best treatment to protect and strengthen the remaining natural tooth structure or improve the tooth’s appearance. They are also recommended for most teeth that have undergone root canal therapy to prevent fracture. A single crown is placed when one single tooth needs reinforcement in isolation. Sometimes multiple teeth need reconstruction and the crowns will be constructed in multiples.
Crowns can be made out of porcelain, gold, or a combination of the two. The appearance of a crown can vary from gold, to all-ceramic crowns, which when completed by a skilled Prosthodontist can be indistinguishable from the adjacent natural teeth. Generally dental crowns are made offsite in a dental laboratory by a dental technician. Prosthodontists will resource very skilful technicians that complete work of the highest standard.
To restore a tooth with a crown usually takes at least two visits following the consultation. In the first visit your Prosthodontist will refill and reshape your tooth to receive a dental crown. At a second visit your Prosthodontist will try-in, adjust and cement your dental crown. There can be many variations on this sequence. The lifespan of a crown varies with the technical skills of the operator and technician, and the material that the crown is made from. In addition every mouth differs in the degree of hostility for the crown. Some mouths are biologically hostile- with high decay rates and poor oral hygiene. Others might be subject to extreme forces. Gold and metal-ceramic crowns have a proven track record of decades of good service. Contemporary dental ceramics used for all-ceramic crowns show promising results, however, have not been used clinically for the same time frame to have an equivalent track record. Full gold, all-ceramic and metal-ceramic crowns may offer different advantages and disadvantages for your specific case, and your Prosthodontist will guide you as to what will provide you with the best clinical outcome.
