In some cases, a tooth may have suffered significant damage for some reason, but still have an intact nerve and some parts of the surrounding enamel remaining. A crown is a synthetic "cap" which is placed over the remaining visible part of the tooth, providing a protective coating for the nerve and remainder of the tooth.
The crown is firmly cemented into place, preventing further damage to the tooth and providing an effective biting and chewing surface.
A crown also has cosmetic value: chipped, broken or partially absent teeth can look unsightly. Made of the correct material, a crown can blend seamlessly with existing teeth, creating an even, attractive appearance and covering the previously jagged or broken surface.
Why might I need a dental crown?
The most common reason for a dental crown is where a tooth has become significantly eroded. This may have occurred because an initial patch of decay wasn't seen and treated in time, or because a dental filling has failed.
Crowns may also be required because a piece of tooth has broken off as a result of an accident or trauma. In some cases the tooth may have been damaged due to infection, or weakened due to an underlying pathology.
Your dentist will be the best person to speak to in order to determine if a dental crown is going to be the right treatment for you, or whether some other form of intervention is going to be more appropriate.
What are the different types of dental crown?
Dental crowns may be made out of:
- Gold alloy
- Base metal or metal alloy
- Porcelain (also known as ceramic crowns)
- Porcelain fused to metal
Each type of crown has its own set of pros and cons: when you have your initial consultation with your dentist, they will go through the various options with you, as well as make recommendations regarding the best type of crown for your individual circumstances.
Gold alloy is one of the most durable crown options. It is also gentle on the surrounding teeth, remaining smooth even with significant wear. One of the main advantages of the gold alloy is that it fixes firmly to the tooth, minimising the risk of detachment at a later date.
The main disadvantage of gold alloy is that it in no way matches the surrounding teeth, meaning it's a bad choice for front teeth or teeth where a natural appearance is required.
Base metal alloy crowns: are also incredibly durable. Where a base metal alloy crown is used, minimal preparation of the tooth is required to enable a firm fix to be achieved. Base metal doesn't corrode easily, helping it to last longer: in some cases, a base metal crown can last an entire lifetime!
Porcelain crowns: can be coloured to exactly match existing teeth. This means they are ideal as a cosmetic crown, where appearance is important. Porcelain crowns are less durable than their metal alloy counterparts. Regular inspection and maintenance of porcelain crowns is essential, as a worn porcelain crown can become rough, rubbing on surrounding teeth and potentially causing erosion.
Porcelain fused to metal: Combining the best of both worlds, crowns which are made of porcelain fused to metal have excellent durability at the same time as looking natural.
Resin crowns: are the cheapest types of crown, but are also the least durable. They may only last a few years after application.
How is a dental crown fitted?
An initial appointment is required, during which the dentist will talk through the various options available to you for your treatment. They may also take some X rays in order to assess the condition of the teeth and gums. Depending on the condition of the tooth being considered for a crown, a root canal procedure may be required.
At the next appointment, the tooth will be prepared for the crown. This may involve the removal of the parts of the tooth which are decayed, as well as filing down any rough edges or uneven surfaces to create a suitable base on which to cement the cap.
If the tooth has large parts missing, material may be put in place to construct a suitable surface on which to mount the crown. A local anaesthetic is given before the start of treatment, ensuring it is as pain free as possible.
Once the tooth is adequately prepared, impressions are taken for the crown. These may be done manually, using special trays filled with an elastomer: a special type of compound that can hold a tooth impression.
Whilst your permanent crown is being made, you will be given a temporary crown (frequently made of acrylic) to protect the prepared tooth surface, fixed in place with temporary cement. Impressions are taken from both the upper and lower jaws.
There is usually a gap of two or three weeks whilst the impressions are sent away for an outside facility to make the crowns. If you have opted for a porcelain crown, your dentist will do appropriate checks to make sure you end up with a crown the same colour as your natural teeth.
When the crown is returned, your dentist will remove the temporary crown and fix the permanent crown in place, using highly durable cement.
How long do dental crown last?
Factors which influence how long a dental crown lasts include: the chewing and biting style of the patient; whether tooth grinding is an issue; the material from which the crown is made; the position in the mouth; and the care taken of the mouth and gums.
Generally a crown will last at least five years, with some (particularly metal crowns), lasting 15 years, 30 years or even a lifetime.
What special care does a dental crown require?
Once fixed in place, dental crowns require the same level and type of care as other teeth. That said, it's important to maintain dental hygiene standards in order to minimise the risk of decay developing in the portion of the tooth, which remains.
How much is a dental crown?
Prices vary depending on the type of crown, where it's needed in the mouth and the charging policies of your surgery. A dental crown usually costs somewhere between $1,100 and $1,800, with the price largely depending on the material used to create it.