Types of Dental Crowns
Dental crowns are often used in restorative dentistry to restore a broken / damaged tooth. There are a number of different types and all have their advantages and disadvantages. Read this article to find out what a dental crown is, when it is used and what the characteristics are of the various types of crowns.
A dental crown is an artificial cap that is tooth shaped. It covers a particular tooth to re-establish its size, shape, appearance and improve its strength.
When the crown is cemented, it completely encases the visible portion of the tooth.
They look just like a natural tooth and last for about seven years. Sometimes, they last up to forty years.
When is a dental crown needed?
After root canal treatment
An accidental injury can damage your tooth. Your tooth has two layers, enamel and dentin and next to dentin is the pulp which is the vital tissue of your tooth. If the pulp is functioning well, your tooth is alive. If your pulp is damaged due to a sudden blow such as an accident, your tooth goes non-vital/ dead.
Dead tooth is weak and can easily fracture. In such cases, crown comes to your help. It makes sure your tooth stands strong as it was before. Your dentist performs a root canal treatment (RCT) for a dead tooth.
In case of structural defects of tooth
Certain diseases such as amelogenesis imperfecta and dentinogenesis imperfecta make your supporting layers enamel and dentin weak. In such cases, crowns are of help.
After large fillings
If the filling is large, it can weaken the tooth as there’s a little of tooth structure remaining. In such cases it can easily fracture but a crown can save your tooth.
Though the broken part of your tooth can be redone with a filling, it may not stand for long. In such cases crown makes sure your tooth is as good as before.
A bridge is a prosthetic device which bridges the gap between two teeth. For placing a bridge, your dentist prepares the adjacent tooth so as to hold the bridge. Usually a bridge has at least two crowns. Your dentist fixes them to your adjacent teeth which act as a support. The supporting teeth are also known as abutments and the artificial tooth that you are replacing is known as a pontic.
Crowns also help implant supported bridges. Implant is an artificial tooth root made of titanium which feels just like your natural tooth. It’s made of titanium and your dentist places it into your jaws via a surgery. Once it heals and implant is well seated, your dentist places a crown or a bridge. In an implant supported bridge, an implant is on one side and the abutment is on the other side. The abutment also needs a crown.
Some teeth may not have an ideal shape since birth. Crown helps such teeth look normal.
Heavily stained teeth
In some instances, teeth are so heavily stained that your dentist cannot completely whiten them, for instance fluorosis. Fluorosis is a condition where there is excess fluoride in water which causes undue stains on your teeth. A dental crown helps you mask those stains.
Sometimes kids’ teeth are highly prone to cavities. In such cases, crown helps to protect your child’s tooth.
For the perfect smile
Sometimes you may want to better your smile. Dental crowns can help you with the shape and shade of teeth that you want.
Procedure for a dental crown
Your dentist also examines your other teeth especially the adjacent and opposing teeth, whether they need any treatment such as fillings or deep scaling / cleaning. These factors decide the success of your crown. If all the adjacent and opposing tissues are in optimal health, your crown can last longer.
Your dentist anesthetizes the area for which you will be receiving a crown. Then, your dentist files your tooth so that it fits the crown well, and this process is known as tooth preparation. If you are going to have a bridge, your dentist will also prepare the adjacent teeth.
Sometimes you need a crown for an implant supported bridge. In such cases, your bridge may have the support of an implant on one or more sides of the bridge.
Then your doctor takes an impression of all the prepared teeth. He/she guides you to choose a crown that perfectly matches with your teeth. Followed by which, your dentist sends it to the lab. It takes around four to six weeks for your crown to be ready.
Meanwhile, your doctor may give you a temporary crown to protect your teeth till your final crown is ready. You will need another appointment once your crown is ready. Your dentist checks the fittings of your crown, makes necessary adjustments and fixes the crown onto your teeth with a cement/dental glue. The dental glue is made of powdered glass or synthetic resin and it cements via resistance, retention or chemical bond.
This is how the process of crowning looks like. Some problems may develop after the crown is cemented like allergic reactions, discomfort, sensitivity, chipping off, loosening, falling off, cracking etc. Generally, a crowned tooth does not require any special care regimen but it also does not ensure complete protection to the underlying tooth from gum disease and infections. Thus, brushing and flossing must be done regularly.
Single sitting crown
You can also get a single sitting crown, which will help you skip the appointments and get everything in a single appointment.
Single sitting crowns are made of ceramic. Here your dentist uses CAD/ Computer Aided Designing and CAM/ Computer Aided Manufacturing technology. After filing your tooth, your dentist uses a special intra-oral camera to take several images of your prepared tooth. With the help of these images, your dentist designs a new crown in the computer.
The dentist does all the fine adjustments for the crown in the computer itself. There is no need to take an impression of your tooth here. The milling machine at your dentist’s office carves a new crown out of ceramic. This process takes just few minutes. Following which your dentist glues the new crown on to your tooth.
See our article about CEREC crowns if you want to know more about same-day dental crowns.
Various types of dental crowns
There are a number of different types of dental crowns to choose from. All have their own advantages and disadvantages:
Full metal crowns
As the name suggests, they are the crowns made of metal. They can also be a combination of various metals which are known as alloys.
- They are stronger and are suited for back teeth. They are tough enough to withstand the chewing forces.
- They do not wear out the opposing teeth.
- They last much longer.
- They provide a stronger seal around your tooth.
- They have a metallic look.
There are several types of full metal crowns.
- Gold crown: It is a combination of gold, copper, and other metals. Captek crown is a new and high quality version of gold crowns.
- Base metal alloy crown: They can be a combination of nickel-chromium or cobalt chromium. They require least amount of tooth to be removed while preparing your tooth for the crown.
- Stainless steel crowns: They are also known as prefabricated crowns. After a root canal treatment, they protect your prepared tooth till your permanent crown is ready. They are also useful in children to protect a decayed tooth which needs a crown. As these are prefabricated, your child can skip the multiple visits for a crown.
They are also known as porcelain or all ceramic crowns. They are made of porcelain.
- They are suited for the front teeth, as they look just like your natural teeth.
- They are an ideal choice for people with metal allergies.
- When you use a porcelain crown, the seal around your tooth depends on the strength of your tooth as well as the kind of filling.
- Their strength is questionable especially if someone has the habit of grinding teeth at night.
There are several types of full ceramic crowns:
- Zirconia crowns are the most durable and natural looking type of teeth crowns. Their only disadvantage is their higher price.
- Emax crowns are probably the most aesthetic type of crowns. They are getting more and more popular for restoring front teeth.
- Lava crown is another newer type of all ceramic crown. Preferred for front tooth restorations.
- CEREC crown - unlike most other crowns, this crown only requires one visit to the dentist.
- These crowns look like your tooth and suitable for front teeth.
- They are economical.
- They are weaker and can fracture easily.
Porcelain fused to metal
PFM crowns have a metal lining inside and porcelain on top of it.
- They are stronger and last longer
- The metal surface bonds better with tooth
- They look opaque, thus may not perfectly match with your natural teeth.
- The metal line at the interface of porcelain and metal may be visible at the gum line. This is truer when gums have recede/ go down towards the base of tooth.
How long does your dental crown last?
On an average, a crown lasts for seven years. However, if you maintain them well, they can last for a lifetime.
7 tips to make sure your dental crown lasts longer:
1. Brush twice a day
2. Floss everyday
3. Avoid grinding your teeth/ biting nails/ opening packages with your tooth.
4. Use a good quality toothbrush, paste, and floss. Though your crown protects your tooth, you have to protect your tooth near your gums. Your dentist may give you a high fluoride gel to protect your tooth against gum infections.
5. Meet your dentist if you face any issues with your tooth/ crown/ fillings.
- Sometimes your crown is over a vital/ living tooth. In such cases, if you experience pain or sensitivity when you bite down, talk to your dentist. He/ she may do the necessary adjustments as per the need.
- If you feel the crown is not fitting well, talk to your dentist. An ill-fitting crown may invite decay.
- After some use, the crown may fall. If it does, keep your crown safe and bring it to your dentist. Your dentist will do a thorough examination and if it’s suitable, he/ she may recement the crown. In situations where you have to replace the crown yourselves, clean the crown thoroughly of any debris or remaining cement. Use a wet cotton swab to do the final cleaning. Cement the crown using a temporary cement or denture adhesive which is easily available. Schedule an appointment with your dentist at the earliest.
6. Schedule a regular dental check-up every six month.
7. If you are having a temporary crown, avoid sticky or hard foods. Avoid chewing from that side.
How much does a dental crown cost?
There is no definitive answer to this question. It depends on the type of the crown, the experience of the dentist, your geographical location, etc.
As a rough estimate, most crowns in the US start around $1000, however if you need any additional treatment, e.g. root canal, the price can easily go up to $3000.
Read our article about dental crown costs if you want to find out more.