Home > Endodontics > Single Tooth Crowns- Metal, Ceramic, Metal with Ceramic
A dental crown is a tooth-shaped “cap” that is placed over a tooth — to cover the tooth to restore its shape and size, strength, and improve its appearance.
The crowns, when cemented into place, fully encase the entire visible portion of a tooth that lies at and above the gum line.
Why Is a Dental Crown Needed?
- 1. To protect a weak tooth (for instance, from decay) from breaking or to hold together parts of a cracked tooth.
- 2. To restore an already broken tooth or a tooth that has been severely worn down.
- 3. To cover and support a tooth with a large filling when there isn’t a lot of tooth left.
- 4. To hold a dental bridge in place.
- 5. To cover misshapened or severely discolored teeth.
- 6. To cover a dental implant.
- 7. To make a cosmetic modification
Different Types of Crowns:
Metal crown : Metal crowns are completely made with metal which has metallic appearance.Due to their limited aesthetic appeal, metal crowns are not commonly used in dentistry today.
Metal-ceramic crown : Metal crowns are sometimes prepared with porcelain fused to them and are referred to as porcelain fused to metal crowns (PFM). They have a strong metal core in the inside and then a layer of porcelain is cemented on it. The final look is that of a natural tooth.
Advantages of PFM crowns:
- In case of purely metal crowns, the metallic shine is a drawback but here the shade exactly matches the shade of the patients tooth.
- These crowns can be easily used on tooth which is visible unlike the all-metal crowns.
- The quality of these crowns is very durable and superior as they have a metal in their core shell.
- They have enough strength, are highly durable, and can easily bear strong chewing forces.
Disadvantages
- There are more crowns that are vulnerable to breaking and chipping as compared to all ceramic.
- In Metal ceramic crown, gum becomes discoloured because of metal present inside.
All-Ceramic Crown:
Glass-Ceramic:
Ceramic crowns are known to grant an absolutely natural look to the crowns which makes them a favourite of the cosmetic as well as dental patients .Emax is an all-ceramic system that is based on Lithium disilicate glass.Emax based all-ceramic prostheses are rapidly gaining widespread popularity in cosmetic dentistry due to their excellent esthetics, durability, and strength.These are the main properties of an Emax crown, which make them one of the best choices to restore your front tooth. The Emax system is mainly indicated for fabrication of crowns and veneers in the anterior region. There is no anaesthetic grey line visibility compared to that of conventional metal-based ceramic crowns.
Zirconium crowns:
Zirconium crowns are made up of zirconium oxide or zirconia. Zirconia is a white powdered metal which has the ability to be radiopaque in the X-rays. There is no grey line visibility compared to that of conventional metal-based ceramic crowns.
The tissues in the mouth happily accept the ceramic crown. Most of the dental crowns undergo corrosion with the years of regular use by the patients. Various fluids and foods consumed over years lead to the corrosion of the dental crowns.Ceramic crowns do not undergo corrosion like most of the other types of dental crowns which contribute majorly to having a long life. These crowns are made with CAD-CAM (Computer assisted designing – Computer assisted milling) technology which is the latest in digital dentistry.
Thus, Ceramic crowns are of great benefit for the individuals who want to get permanent aesthetic solutions for their damaged teeth.Ceramic crowns are one of the best treatment options in the modern times.
Benefits of BRIDGES & CROWNS
In addition to strengthening a damaged tooth, bridges and crowns can be used to improve a tooth’s appearance, shape, alignment and dental occlusion (bite). Gaps left by missing teeth can cause the remaining teeth to shift, which can result in a bad bite. Bridges and crowns help prevent this from happening.
FAQ’s :
1. Are metal crowns safe?
Metal crowns are a good choice for out-of-sight molars. Porcelain-fused-to-metal and ceramic dental crowns can be color matched to your adjacent teeth (unlike the metallic crowns). However metal crowns undergo corrosion over a period of years and it has unsightly appearance.
2. What type of metal is used in dental crowns?
Porcelain fused to metal crowns are cast metal crowns which have a porcelain covering over it. The tooth colored ceramic is baked on top of a metallic alloy substructure made of cobalt-chromium.
3. Are metal crowns better than porcelain?
The most commonly used is the porcelain fused to metal crown (a PFM) and all ceramic crown. All metal crowns have traditionally been the strongest, but today most people want a more cosmetic alternative. Porcelain to metal or all ceramic crowns offer high strength with better cosmetics — a crown that matches the color of the other teeth.
4. How long should a tooth crown last?
Dental crowns last on average between 5 and 15 years, depending on how well they are made and cared for. To extend the longevity of your crown, you should refrain from habits such as biting your nails or opening packages with your teeth. These can put excessive pressure on a crown and shorten its lifespan.
5. What is a PFM crown?
A PFM crown is composed of a metal base over which we attach layers of porcelain. This combines the esthetic beauty of ceramic with the sturdiness of metal. It is a perfect solution for patients whose teeth are severely damaged, or for patients who require placement of long bridges and who cannot afford for all-ceramic crowns.
6. Which tooth crown is best?
The most commonly used is the porcelain fused to metal crown (a PFM). The second kind of crown is the full ceramic crown which is double the strength of PFM.
7. What is zirconia crown?
It is extremely strong, requiring less tooth preparation than other materials. It can be layered with porcelain, further improving its aesthetic appearance. Zirconia crowns can be bonded or cemented, giving your dentist more options.
8. Which is better veneers or crowns?
Both crowns and veneers are effective in improving the aesthetic appearance of teeth. A veneer is usually made of wafer-thin porcelain and is bonded to the front of a tooth. Veneer require very minimal tooth structure then crown. A crown encases the entire tooth.
