What are dental crowns?

Over time, your teeth can get damaged. This can happen for a variety of reasons, like tooth decay, injuries or just use over time. Your teeth can lose their shape or size. Dental crowns are tooth-shaped “caps” that can be placed over your tooth. Think of it like a snug hat for your tooth. The crown restores the tooth’s shape, size, strength and appearance.

The dental crown is cemented into place on your tooth and it covers the visible portion of the tooth.

Why would I need a dental crown?

You may need a dental crown for several reasons, including:

  • Protecting a weak tooth (possibly from decay) from breaking or to keep the weak tooth together if parts of it are cracked.
  • Restoring a broken tooth or a severely worn down tooth.
  • Covering and supporting a tooth with a large filling and not much tooth remaining.
  • Holding a dental bridge in place.
  • Covering misshapen or severely discolored teeth.
  • Covering a dental implant.
  • Covering a tooth that’s been treated with a root canal.

What are onlays and 3/4 crowns?

There are many types of crowns that can be used on your teeth. Onlays and 3/4 crowns are types of dental crowns that don’t cover as much of your underlying tooth as traditional dental crowns. A traditional crown will cover your entire tooth. Onlays and 3/4 crowns may be appropriate when you still have a solid tooth structure. It’s considered a more conservative approach compared to full coverage of your crown. In this procedure, your dentist removes the affected area and performs a reshaping of the tooth to receive the crown.

What are dental crowns made of?

Permanent crowns can be made out of many different materials. These materials can include:

  • Metal: There are several metals that can be used in dental crowns, including gold, palladium, nickel and chromium. Metal crowns rarely chip or break, last the longest in terms of wear down and only require a small amount of your tooth to be removed. They can also withstand biting and chewing forces. The metallic color is the main drawback of this type of crown. Metal crowns are a good choice for out-of-sight molars.
  • Porcelain-fused-to-metal: This type of dental crown can be matched to the color of the teeth that’s next to the crown. They have a more natural tooth color. However, sometimes the metal under the crown’s porcelain cap shows through as a dark line. Other cons include the chance of the crown’s porcelain portion chipping or breaking off and the crown wearing down the teeth opposite it within the mouth. This wear on the other teeth specifically affects the teeth that come into contact with the crown on the top and bottom of your mouth when it’s closed. Porcelain-fused-to-metal dental crowns can be a good choice for front or back teeth.
  • All-resin: Dental crowns made out of resin are generally less expensive than other crown types. However, they wear down over time and are more likely to break than porcelain-fused-to-metal crowns.
  • All-ceramic or all-porcelain: These types of dental crowns provide the best natural color match compared to any other crown type. They’re also a good choice if you have metal allergies. However, they aren’t as strong as porcelain-fused-to-metal crowns. They can also wear down the teeth opposite them in the mouth a little more than metal or resin crowns. All-ceramic crowns are a good choice for front teeth.
  • Pressed ceramic: These dental crowns have a hard inner core. Pressed ceramic dental crowns replace the metal liner that’s used in the all-ceramic crown-making process. Pressed ceramic crowns are capped with porcelain, which provides the best natural color match. They’re also more long-lasting than an all-porcelain crown.

Last reviewed by a Cleveland Clinic medical professional on 01/14/2020.

References

  • American Dental Association. Crowns. Accessed 8/27/2020.
  • Arvind Shenoy and Nina Shenoy. Dental ceramics: An update. J Conserv Dent. 2010 Oct-Dec; 13(4):195–203.
  • Academy of General Dentistry. What Are Crowns? Accessed 8/27/2020.
  • American Academy of Cosmetic Dentistry. Porcelain Crowns. Accessed 8/27/2020.

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