Dental Crowns – How They Are Made

Dental crowns are used to encase teeth, binding broken and decayed ones together as well as shielding them from plaque and further damage. They also help to improve the appearance of misshapen or crooked teeth.


Some tooth fractures extend too far into the softer dentin layer for fillings to repair them. Our dentists may then recommend a crown to protect the tooth.

Reshaping the Tooth

Tooth reshaping is necessary to ensure that the crown will fit the tooth properly. If the crown doesn’t have a good fit, it can cause problems such as discomfort, an uneven bite and even further damage to your teeth.

Your dentist will use anesthetic to numb your tooth and surrounding tissue before reshaping it. Typically, you will be left with only minor sensitivity for about a day after the procedure.

Metal crowns are a type of dental restoration that is made out of specific types of metallic alloys. Alloys are metals that contain more than one pure metal and combine their different properties to create a better overall result than any of the elements would be able to achieve on their own. Metal crowns require the least amount of natural tooth structure to be removed, and they are able to withstand biting and chewing forces very well. However, they are not as aesthetically pleasing as ceramic or porcelain crowns.


After reshaping the tooth, your dentist will use a putty-like material to take an impression of it and the teeth either side. A good impression will give the lab technicians exactly what they need to construct a crown or other restoration.

The dentist mixes the impression material – typically alginate or polyether vinyl siloxane – with water until it has the consistency of putty. They then place it in a u-shaped tray that fits over your upper or lower teeth (or both). The tray is held firmly against your teeth and gums for two to three minutes. When the impression is removed, it will still look like putty but should be firm and rubbery.

The dentist takes a very accurate impression, minimising distortion, air entrapment and other defects that can lead to problems with the final restoration or appliance. They check the impression under bright light to make sure that it accurately records the crown preparation and the teeth either side. If not, the impression will need to be retaken. Taking an impression is a difficult job for some patients and they may experience discomfort or a strong gag reflex during this time.

Preparing the Tooth for the Crown

After numbing the tooth and the surrounding area the dentist will start to shape it for the crown. This will involve filing down the chewing surface and the sides-the extent of this depends on the type of crown being made. Metal crowns, for example, require less filing than porcelain ones. X-rays will be taken and the dentist may recommend a root canal if there is risk of infection or damage to the tooth’s nerves and blood vessels.

Using a putty-like material some dentists will take a cast of the prepared tooth and the teeth either side to ensure that the new crown fits perfectly. Other dentists use a digital scanner to take the impression.

In the meantime the dentist will place a temporary crown-usually a resin or acrylic one. This will prevent bacteria from getting into the dentine tubules directly connected to the tooth nerve (if it is still alive) and causing infection or damage. It will also stop the tooth shifting or rotating into an empty space-a condition known as malocclusion which can cause temporomandibular joint (TMJ) problems.

Making the Crown

Once the tooth and gum tissue are numb, the dentist begins to make your crown. They may take X-rays of the trimmed tooth and mouth before making an impression to ensure a good fit.

The type of crown your dentist uses depends on what type of tooth repair or filling you had done previously. All-metal crowns require less natural tooth structure to be filed down than PFM (porcelain fused to metal) crowns. They can be made of gold, silver, chromium, or any combination of these elements. Often, crowns aren’t made out of pure metal because no single element has the ideal physical properties for dental applications. Instead, they’re crafted from alloys, which are mixtures of two or more pure metal elements.

CAD/CAM technology allows dentists to produce and place ceramic crowns in one visit. They use a scanning device to take pictures of the tooth and upload them into software. Then they use a machine to carve the crown out of ceramic in about 15 minutes. The crown is bonded to the tooth using a tooth-colored resin that is similar to dental bonding.

Attaching the Crown

Once the crown has been constructed, your dentist will cement it to the tooth. Typically, they will use dental cement or composite resins that are color matched to the surrounding teeth.

There are many types of crowns that can be made. Traditional metal crowns, for example, are created from alloys with a high percentage of gold or platinum and a lower concentration of base metals (like cobalt-chromium or nickel-chromium) that increase corrosion resistance and strength. These are often used for back molars where durability is more important than appearance.

Other crowns are fabricated using porcelain fused to a ceramic core for strength and a natural translucent appearance. These are often used for front teeth where a natural looking restoration is desirable.

Some offices have CAD/CAM machines that can construct and place a crown in the same day, eliminating the need for X-rays or a lab visit. These are usually’monolithic’ crowns made from a single uniform block of Zirconia and are also sometimes called all ceramic or emax crowns. This is a great option for people with busy schedules who need to fix a broken tooth quickly.