What is a dental crown?
A dental crown is a tooth-shaped shell that sits completely over your tooth. It acts like a helmet against the forces of chewing, protecting the tooth underneath, giving it back the size and shape to allow you to chew properly.
A crown may also be called a ‘cap’ and is a great way to restore teeth which are heavily broken down. It may also be carried out for cosmetic reasons.
Why do I need a crown?
If a tooth has a very large amount of decay, then a crown becomes a more dependable long-term solution. A crown will help to protect the remaining tooth structure underneath.
Sometimes you may have had a large filling that has failed or broken. If the tooth cannot be repaired or re-filled, the most sensible option is to progress to a crown.
If a worn teeth need to be built back to their original height, crowns can help accomplish this when composite bonding cannot be used. When crowns are being placed for severely worn teeth, multiple crowns are generally required.
Crowns can change the colour and the shape of teeth to improve their appearance. Cosmetic crowns and veneers can be discussed with your dentist alongside the alternative options. Crowns require preparation of teeth, so please bear this in mind if you have unrestored teeth and are considering crowns for cosmetic reasons.
A previous crown has failed
Once you have a crown, from that point on, you are always going to need one. So if a crown fails, another crown will be needed to replace it.
To hold together a cracked tooth
If a tooth has a crack, often called cracked tooth syndrome, it can need a crown to hold the tooth together, ensuring even pressure on the tooth to prevent the crack from extending further.
A root filled tooth
Teeth that have been root filled are much more brittle than living teeth. They can fracture easily with uneven pressure, so it is the recommendation that root filled teeth are covered with a crown to strengthen the weaker tooth.
While a tooth can still potentially fracture, a crown makes this much more unlikely, so the sooner this is done following the root canal the better.
How long do crowns last?
On average a dental crown can be expected to last 15-20 years, but it is not unusual for it to last considerably longer.
So what are the choices for my crown?
The main types of crown available are:
Porcelain fused to metal crowns - These have been the staple of the crown world for many years and with good reason. They look good and are very strong. They have a proven track record for success for all teeth.
Zirconia crowns - Zirconia is a very popular material, some crowns are made purely of zirconia making them very hard. The advantage is that you do not need to remove too much tooth as the material is very strong in thin sections. Colour matching can be tricky as they are milled from one block.
Gold crowns - Gold is the gold standard for teeth due to its similar wear pattern to natural tooth. Gold is the most durable, predictable and best tolerated of all the crown materials.
All-ceramic crowns - All-ceramic crowns look very good and natural which makes them highly aesthetic. Without the metal substructure they have improved optical qualities - the way light passes through the tooth. These have a zirconia or aluminiumious core which is then layered with porcelain to make them look like a natural tooth.
All-metal silver crowns - These require a minimal amount of the tooth to be prepared preserving the core for maximum strength and retention. One disadvantage is colour as they are fully silver.
There are some restrictions on the types of materials clinicians can provide in certain teeth under the NHS. Your dentist will discuss the crown options with you.