What are Dental Crowns?
A dental crown (also known as a cap) is a strong unistructure that is man-made but has the natural shape and anatomy of the tooth of which it is covering. It is usually cemented with dental cement or bonded with composite resin material. Because it is fixed onto a tooth, the crowned tooth will feel and function like a tooth, and only dentists can remove the crown if needed.
Why do we need Dental Crowns?
Your dentists may suggest you getting a crown for a tooth or a group of your teeth for the following reasons:
- When the tooth is structurally weak – due to excessive loss of tooth structure secondary to large caries and or root canal therapy (endodontic treatment).
- When the tooth is missing a big area (extensively chipped).
- When the appearance, shape and function of a tooth are not desirable.
- When the patient is a bruxer (clench and grind teeth forcefully) or has heavy occlusal biting force – a regular fillings will not be able to withstand the biting force.
- When the tooth is not in alignment with the adjacent teeth – a crown can make the tooth looks straight and in alignment.
- When there is a missing tooth or some missing teeth, crowns can be placed on the teeth adjacent to the space to support the false teeth filling up the space. In this case the prosthesis is called a bridge.
- When there are implants, then crowns are used to attached to the implants.
- When there is a need to change the shape of the tooth on which a removable partial denture is engaged to. The crown can be incorporated with some special attachments and rests so that the denture can be more stable and natural looking without metal clasps showing in the month.
- When all the teeth are worn down so much that we need to re-establish the original vertical heights of the teeth.
What does your dentist do to make you a Dental Crown?
First your dentist decides the type and designs the shape of the crown based on the purpose of the crown. Then he or she will shave the surface layer off of all the sides of the tooth.
Then an impression of the prepared tooth is taken using silicon-based material on a tray. The tray with the precise impression of the tooth and its surrounding structures is sent to a dental laboratory to be processed for a crown.
With the advent of the digital imaging technologies and the computer-aided design/computer-aided manufacturing (CAD/CAM). There is no need to take an impression using silicon-based material. Instead, a digital camera can be used to capture the shape of the prepared tooth as well as the surrounding structures and the opposing teeth. The digitalized image can then be sent via the internet to a dental laboratory to have a crown processed there.
Some dental clinics may also have their in-house CAD/CAM milling machines to design and mill the crowns out within an hour while the patients are waiting.
If the crowns are not made in-house, then it will take about a week or two before the crowns can be ready. Your dentist may place a temporary crown while the permanent (a common term that is a misnomer because it really is not permanent) one is being made in the dental laboratory.
What are the different types for crowns?
There are four major types of dental crowns.
- Gold alloys – These crowns are made with a mix of gold, palladium, platinum, and silver etc. They are strong, nor do they crack or chip. They are kind to your natural teeth as they are not coarse and abrasive to the opposing teeth during chewing and grinding.
- Ceramic — These are used for restoring front teeth and are popular in this area for their ability to blend with your natural tooth color. There are different kinds of ceramic with different physical and aesthetic properties. They are generally strong but brittle. Therefore, they can be chipped and fractured off under excessive stress or prolonged wear.
- Porcelain-fused to metal (PFM crowns) – These crowns intend to provide a mixture of strength of metal and beauty of porcelain. However, the porcelain can still be chipped off from the metal substructure. The other drawbacks are the difficulty in matching the chroma, value and translucency of a natural tooth with a PFM crowns.
- Base metal alloys – These crowns are made up of non-noble metals that are highly resistant to corrosion and make for a very strong crown. It also requires the least amount of healthy tooth to be removed prior to fitting.
In my next blog, I am going to explore the different types of crowns and their respective uses in more details.
At Affinity Dental Care, we provide different type of crown and bridge treatments to our patients based on the needs and best option criteria. We always put our patients’ health and well-being in the forefront.