A Comparison of Dental Crown Materials

Posted by Peter Young on January 11th, 2021

Dental crowns are tooth-shaped caps that are used to support weak teeth, restore fractured or badly damaged teeth.

Crowns have been around in modern dentistry for decades. Companies, scientists, and dentists keep developing better and better materials to use for restoring a tooth. This goes to say that the materials that were state-of-the-art 10, 20, or 30 years ago might be outdated now.

But what materials do dentists use when crowning a tooth?

1. Base metal crowns

This is one of the oldest, tried, and tested materials of dental crowns. Base metals like silver, cobalt-chrome, or nickel are used to manufacture this crown.

The advantages of base metal crowns:

• great physical properties, they are very durable
• they require relatively little trimming of the tooth
• affordable, compared to other crowns

However, base metal crowns are not used nowadays, simply because the following disadvantages outweigh the benefits:

• esthetically not at all appealing
• some people might be allergic to the metals used

2. Noble and high-noble metal crowns

Commonly called gold crowns, these crowns have a combination of metals like gold, platinum, silver, palladium, copper, and tin.

Gold crowns have both the pros and cons of base metal crowns, except for allergic reactions and price.

Gold is considered to be biocompatible, allergic reactions to gold are rare.

As for the price, high-noble metal crowns are usually expensive, because the metals used are expensive.

Even though the dentist like this material, because of its biocompatibility and great physical properties, their price and low esthetic appeal make them fairly unpopular.

3. Porcelain fused to metal crowns

To overcome the limited esthetics of metal crowns, researchers created a crown type known as porcelain fused to metal crown (PFM crown).

This is a metal crown with a layer of porcelain fused to the metal. Thanks to this porcelain layer, PFM crowns look a lot better than metal crowns.

Because of this increased esthetic appeal, these crowns used to be very popular. They are still in use today, albeit they are not as popular as they used to be.

PFM crowns also have a few disadvantages:

• because of the two layers (metal & porcelain), this crown is thick and require a fair amount of tooth to be removed
• the porcelain layer might chip off when chewing hard food
• a black line at the gumline tends to appear after a few years
• a PFM crown still includes metal, which might cause allergic reactions

Also, they are not as translucent as your natural teeth, sometimes the metal layer might give a darker shade to the crown. This means PFM crowns are still not ideal restoration for front teeth.

It's also worth noting that the metal in these crowns might be either base metal or high-noble metal.

Porcelain fused to base metal crown might be more affordable than porcelain fused to gold one, however, in terms of oral hygiene and biocompatibility, the gold is preferred.

4. Ceramic crowns

The disadvantages of PFM crowns further incited research on dental crown materials and led us to the world of all-ceramic crowns.

These crowns are completely metal-free, very durable, and look like your natural teeth.

Materials like zirconia or lithium disilicate (for E-max crowns) are used most often.

All-ceramic crowns are now the rage in cosmetic dentistry. Dentists prefer to use these crowns for both front and back tooth restorations.

They have several advantages:

• metal-free, no allergic reactions
• very strong and durable
• look very natural
• not significantly more expensive than gold or porcelain fused to gold
• can be manufactured in the dentist office (see below)

and a few disadvantages:

• they are so tough, that they might wear-off the opposing tooth
• if there are secondary caries under the crown, it's hard to notice it

So which material should you choose?

While all-ceramic crowns are usually a good choice for both front and back teeth restorations, a gold or PFM crown might also be fine, especially for back teeth.

We recommend consulting with your dentist and making sure you are aware of both the pros and cons of the different crown types.

+1 Same-day crowns

Ceramic crowns made a new and interesting advance possible: same-day dental crowns.

Traditionally a dental crown procedure requires two visits to the dentist. During the first visit the tooth is trimmed, an impression is taken and a temporary crown is fitted.

Then the patient has to wait 5-15 days until the lab finishes the permanent crown.

This permanent crown is fitted on the second visit.

Nowadays with the help of computers, a dental crown can be manufactured in the dental office within an hour.

The crown is manufactured by a CAD-CAM device from a monolithic block of zirconia.

It usually takes less than two hours to get such crowns, no awkward impressions or temporary crowns, no waiting for the lab.

The only drawback of same-day crowns is that not many dentists offer them and it requires some experience to fit them perfectly.