• Dental crowns are tooth-shaped caps. They can be made of a variety of materials, including all-ceramic, zirconia, and porcelain fused to metal.
  • Crowns can be used for three reasons: to cover another treatment, for support, or for aesthetic reasons.
  • Dental crowns can also be used to restore teeth that have had large fillings or root canal treatment. They can support dental bridges and teeth that are cracked, worn, or weakened by disease.
  • Need a new dental crown fast? Use Authority Dental to book a 24 hour emergency dentist near you. It’s simple, fast and free.

What type of dental crown should you choose? Here's everything you need to know.

When are crowns recommended?

There are 3 main reasons for getting a crown:

  • to cover up some other treatment,

  • for support, or

  • aesthetic reasons.

A crown may cover the tooth fully or partially up to the gumline. This, and the price for a dental crown both depend on the condition and health of the existing dentition.

Crowns can restore teeth that had large fillings or root canal treatment, and go on top of dental implants. They may also support dental bridges and teeth that are cracked, worn down, or weakened by disease. All of these to protect the existing dentition and prevent further damage.

When it comes to aesthetic reasons, such a restoration can help in altering the color, shape, or size of the tooth. If all you want to change is the appearance of the tooth, you may want to consider veneers instead.

Types of crowns

There are a few types of dental crown. You can differentiate between them by the material they are made from.

All-ceramic

Ceramic dental crown

Picture by Authority Dental under CC 2.0 license

A dental crown made entirely of porcelain is referred to as “all-ceramic”. Nowadays it is the most popular type of crown.

The biggest advantage is that it provides great aesthetics. It can match the shape, size, and color of the surrounding dentition perfectly. That’s why it is recommended as a front tooth crown and commonly performed by cosmetic dentists.

Namrita Harchandani

Namrita Harchandani, DMD

Dental crowns are the best way to protect the original natural tooth. With the advancements in dental technology and materials, very realistic crowns can be made that will make you forget that you even have one.

Porcelain is also biocompatible and toxic-free. This means it won’t cause an allergic reaction, as metal crowns sometimes do. The downside is that it is quite pricey.

Lithium disilicate is one type of porcelain. Some clinics have equipment that allows making such crowns in-office. This means the crown doesn’t need to be sent over to the lab, and that can save a lot of time.

Despite being the most expensive crown material, it is not the most durable. It can last a long time, but not quite as long as metal. What’s more, it does wear down the opposing tooth (the one it bites down on).

  • Great aesthetics

  • Lithium disilicate can be made in one visit

  • Biocompatible and toxic-free

  • Expensive

  • Not the most durable

  • Wear down opposing teeth

  • Often can’t be done in one appointment

Zirconia dental crowns

Zirconia dental crown

Picture by Authority Dental under CC 2.0 license

Zirconia crowns combine the strength of metal and the convincing appearance of porcelain. Those suffering from allergies can also safely choose this material. It is biocompatible, so it doesn’t cause adverse reactions. Such crowns are becoming more and more popular.

They can also be layered with porcelain to further improve the appearance. If that is not done it can be difficult to match the exact color of the surrounding teeth, as zirconia is very opaque.

Sayeh Hadianfar

Sayeh Hadianfar, DDS

Progressive dental laboratories have solved the issue of the transparency of zirconia. They are able to match the shade of the patient's other teeth.

Zirconia crowns can sometimes be milled at the dental office. This means it could be done in one appointment, or at least in one day. You may not need a temporary crown. What’s more, the material is very strong and requires less tooth preparation. It can be bonded or cemented, so the dentist has more options.

The downsides are that the material makes these crowns difficult to adjust, they’re expensive, and they do wear down the tooth they bite on. That being said, they are unlikely to wear down or chip themselves.

  • Strong and durable

  • Can look great

  • Biocompatible and toxic-free

  • Sometimes can be done in one appointment

  • Less tooth preparation

  • Expensive

  • Difficult to adjust

  • Wear down opposing teeth

Porcelain Fused to Metal Crowns (PFM)

 Porcelain fused to the metal PFM dental crown

Picture by Authority Dental under CC 2.0 license

Porcelain fused to metal (PFM) means that the crown has a metal base and a top made of porcelain. The porcelain top allows the shape, size, and color of the surrounding teeth to be mimicked. It may not be the most popular, but it is widely used.

It is among the strongest and most durable and it is less costly than the all-ceramic or zirconia crown. But such a crown does have its drawbacks.

The biggest downside of PFM crowns is a gray line between the tooth and gum that is sometimes visible. What’s more, if you are prone to clenching, it can chip or damage the opposing teeth. It can also cause allergic reactions.

This type of crown cannot be done in one visit like some of the ones described above. You will have to wear a temporary one.

  • Shape, size, and color can be mimicked

  • Strong and durable

  • Less costly

  • Grey line between the tooth and gum

  • Can chip or damage opposing teeth

  • Cannot be done in one visit

  • Can cause allergies

  • Need more tooth reduction

All-metal crown

Metal gold dental crown

Picture by Authority Dental under CC 2.0 license

An all-metal crown is the strongest and most durable type, but it is not as aesthetically pleasing. While the shape and size of the surrounding teeth can be mimicked, the color remains different.

They are usually used for back tooth restoration. Some do, however, like this aesthetic and even go as far as engraving it or adding gems.

Unfortunately, all-metal crowns can cause allergic reactions. They are usually a mix of materials such as gold, chromium, palladium, and silver. The amount of gold in the crown can range from 20% to 77%.

Matthew Stewart

Matthew Stewart, DDS

While it is technically possible, the likelihood of an allergic reaction is extremely rare. About 1 in 100,000. A metal crown is not advised against, unless the patient has history of allergic reactions to dental work.

There are ratings that provide info on the metals used. The ratings are named “Base Metal”, “Noble Metal”, and “High Noble”. The last type has the highest percentage of gold.

These crowns tend to be the best fitting and least damaging to opposing teeth.

The upside for these is that less of the tooth has to be removed than for other materials and they wear down at a rate similar to enamel. The downside is that they cannot be completed in one visit and you do have to wear a temporary crown.

  • Strongest and most durable

  • Shape and size can be mimicked

  • Less of the tooth has to be removed

  • Wear down less than other types

  • Don’t wear down the opposing teeth very much

  • Cheaper than other options

  • Recommended for patients who grind

  • Not aesthetically pleasing

  • Can cause allergic reactions

  • Cannot be completed in one appointment

Provisional crown

Provisional temporary dental crown

Picture by Authority Dental under CC 2.0 license

A provisional crown is what you wear while you wait for your permanent crown. It can also be described as “temporary”. It is made from materials that aren't meant to last very long and it is not permanently attached.

It shouldn’t be worn for more than a few months to a year at most. Most of the time it stays in the mouth for less than two weeks. The longer you wear it, the more problems it can cause.

A temporary crown is usually included in the price for the permanent crown. It is a necessary step if you have to leave the office before the permanent crown is ready, otherwise you could damage your living tooth.

Dental crown procedure

The tooth crown process can be divided into seven generalized steps. Some might not apply to every case. You will most likely have some sort of oral examination first, but after that it usually takes a few weeks to get a permanent crown.

Preparation of the tooth

The tooth crown procedure begins with removal of the decay, performing the root canal treatment if necessary, or both. The affected area will be numbed with a local anesthetic. The tooth will be shaved down as necessary.

Post and core buildup

You might need additional steps to build up your foundation, depending on the state of the tooth. The most common way is a post and core buildup. This is recommended for teeth which have suffered considerable decay. This step can sometimes be done at the same time as preparation or shaving of the tooth.

Making a mold or scanning the tooth with a digital device

An impression can be made to make sure the crown fits perfectly. Some dentists prefer to use a scanner instead of the unpleasant putty. The opposing tooth can also be recorded so that the bite is comfortable.

Determining the shade

This can be done by using a shade guide or taking pictures of the teeth. It will help the lab technician make crowns that will match the rest of your teeth. In some cases the dentist may refer you to a ceramist for perfect shade selection.

Temporary dental crown

A provisional crown will be made from resin or acrylic. It will come off easily when it is time to place the permanent crown. During this time be sure to avoid eating hard or sticky food, as the temporary crown can crack or fall off.

Crown fabrication

There might be a few weeks between placing the provisional crown and the next appointment.

Permanent crown placement

Lastly, the permanent crown will be placed and inspected for proper fit, bite, and smooth surface. Adjustments may need to be done, such as for the color or rough spots. Afterwards the crown will be attached by cement or dental glue. This is permanent and no more changes can be made.

FAQ

How long does a tooth crown last?

Longevity of crowns depends on the material they are made from, how well you take care of them, and its location. Porcelain crowns can last between 5 and 15 years while PFM ones last about 20. The most durable are all-metal crowns, and they can last over 20 years up to a lifetime.

What does a dental crown look like?

A properly designed dental crown should look very similar to natural dentition. If you decide to go with a PFM crown, there might be a small grey line by the gums.

How much tooth structure is needed for a crown?

The minimal height of intact tooth structure above the gum needed is 1.5-2 mm.

How much tooth crown pain will I experience?

Since an anesthetic will be used to numb the dental crown pain, you should feel no more than slight discomfort during the procedure. It is common to experience tenderness in the gums surrounding the crown. This is because the dental cement can irritate them.

Pain in the tooth with the crown when biting down is completely normal. Treat this with OTC painkillers and keep the area clean. Toothpaste for sensitive teeth and gums is also a good idea. The unpleasant feeling will subside within a few days. The pain shouldn’t be severe or stretch over several weeks. If the tooth continues to hurt, make an appointment with your dentist. Sometimes a simple adjustment is enough to solve the problem.

Can your teeth rot under the crown?

Yes, especially if you don’t take good care of it. Decay around the edges of the crown can be easily detected. If treated soon enough, you might be able to keep your crown for many years. This is one of the reasons that bi-yearly exams are recommended.

How to fix a broken crown tooth?

If the damage isn’t extensive, the dentist may be able to fix a crack or chip with resin. Porcelain crowns, however, may have to be completely replaced.

References

  1. Dental crowns