Chances are you’re reading this blog because you’re researching restoration options or considering getting a dental crown. Your dentist has mentioned crowns, and now you started to wonder, “What are dental crowns and how do they help?” Thankfully, this blog will dive into the different types of dental crowns and how you can benefit from receiving one.
What Is a Dental Crown?
A dental crown is a custom-made, permanent dental restoration. A crown is a hollow, tooth-shaped “cap” placed over your natural tooth. Crowns completely cover the visible portion of the tooth above the gum line. Crowns are also used as implants to replace missing teeth lost to disease, decay, or an accident.
Why Would You Need a Dental Crown?
A crown is meant to restore a tooth’s strength, functionality, shape, and size, improving its appearance. Situations where you might need a crown include:
- To protect a weakened or cracked tooth preventing breaking.
- To replace an old, broken, or failing tooth filling.
- To restore a broken tooth.
- To restore length on worn down teeth from grinding.
- To cover and support a tooth with a large filling when there isn’t much natural tooth structure left.
- To make a cosmetic modification such as closing spaces between teeth, reshaping, or rotating teeth.
- To hold dental bridges in place.
- To cover a dental implant.
- To restore strength to a tooth that has undergone a root canal.
The Different Types of Dental Crowns
Permanent dental crowns can be made from:
- Stainless steel
- Resin materials
An all-metal crown means the entire crown is made out of metal, metal alloys, to be specific. These are the strongest types of crowns available. Metal crowns require the least amount of tooth structure to be removed, preserving the tooth’s core for maximum strength and retention. They rarely chip, fracture, or break and don’t wear down the other teeth they bite. They also last the longest in terms of wear. The big drawback of these crowns is the metallic color and the lack of a natural appearance. However, they are a good choice for out-of-sight molars.
An all-ceramic crown is made out of ceramic material. All-ceramic dental crowns provide a natural appearance and color match, making them the most natural-looking option for front teeth. The goal of creating a ceramic crown is to mimic a natural tooth’s light handling characteristics and appearance. Dental laboratory-produced crowns use different types of porcelains, each with different shades and translucencies in multiple layers to create the crown. There are also computer-designed and manufactured machine-produced crowns. These are milled out of a single block of ceramic material. These crowns have one shade and are not as translucent but still match the color of natural teeth.
Some disadvantages of ceramic crowns are that they wear down opposing teeth more than metal and resin crowns. They also require more tooth structure to be removed because of the thickness of the porcelain required for sufficient crown strength. The major risk with ceramic crowns is that they can fracture, leading to infection and failure if not treated by a dental surgeon.
Porcelain Fused-To-Metal Crowns
Porcelain-fused-to-metal (PFM) crowns are made of metal and porcelain. The core that sits under the crown is metal, and porcelain is layered over and bonded to the metal base to give the crown a tooth-like shape and color. A PFM crown is suitable for either front or back teeth. Next to all-metal crowns, they are the second most long-wearing choice. Next to all-ceramic crowns, PFM crowns most closely resemble natural teeth. However, because the metal core of a PFM crown is so dark, it needs to be covered in very opaque porcelain to mask the metal color. As a result, only a thin layer of translucent porcelain can fit on the top, reducing the ability to truly mimic the lustrous look of a natural tooth.
The major risk with PFM crowns is that the porcelain layer can fracture, leading to infection and failure if not treated. The porcelain used is also quite abrasive and can wear down opposing teeth. Another disadvantage of PFM crowns is that, over time, the underlying metal can show through as a dark line.
Stainless Steel Crowns
For adult dentition, prefabricated stainless steel crowns are used temporarily to protect the tooth or filling until the permanent crown has been manufactured. However, stainless steel crowns are commonly used for primary teeth in children. The crown fits over a prepared primary tooth, covering it entirely and protecting it from further decay. When the primary tooth eventually falls out, the crown naturally comes out, too. Stainless steel crowns are favorable in children’s dentistry because they require minimal dental visits to fit and cement. They are also a cost-effective option for a primary tooth that will eventually be lost anyway.
An all-resin crown is made out of resin material. All-resin crowns are made from composite resin material – a combination of plastic-type materials that are colored to look like natural teeth. Common resin varieties used to create these crowns are silicon dioxide resin, Polymethyl Methacrylate resin, or acrylic polymer resin. All-resin crowns are used temporarily to protect a tooth or filling until the permanent crown has been manufactured. They are a metal-free alternative to stainless steel temporary crowns and can be mixed in several shades to match the tooth’s natural color. Patients may find this more aesthetically pleasing than the stainless-steel option.
Resin crowns are often only used temporarily because they wear down over time and do not withstand biting and chewing very well. They are also relatively vulnerable to fractures compared to other crown types. However, they are relatively inexpensive compared to the other durable crown types. If they are to be used as crowns, they are most suitable for restoring the front teeth. They are also a good alternative to straight fillings because they can be wrapped around the entire tooth’s surface for strength and durability.
Post and Core
A core or post and core may sometimes be required before a crown is cemented. Successful dental crown placement depends on the amount of tooth structure in the natural tooth. A solid core provides adequate stability for the crown. Core placement refers to a procedure where the missing natural tooth structure is replaced with a filling before the cementation of the crown. By rebuilding the tooth with an artificial core, the stability of the crown is increased, maximizing the long-term prognosis for the new restoration. If sufficient lower tooth structure remains to support it, a core filling is all that’s needed to provide a foundation for the crown. If not, a metal post is inserted into the root canal first to help anchor the core filling to the tooth. Many dental post systems are available, including parallel-sided, tapered, threaded, and serrated, all made from metals such as titanium or stainless steel. Your dentist will select the most appropriate post variety for your case.
A dental core can be used on any tooth, but a post and core can only be used on a tooth that has had root canal treatment. The root canal allows the post to extend deep into a hollow root canal of the tooth. A tooth that has undergone root canal therapy will always need a post inserted to provide sufficient stability for a crown.
What Is Involved in a Dental Crown Procedure?
Dental crown procedures will vary depending on your case, but this is a general overview of what to expect. The dentist will perform an initial examination of your tooth and overall mouth. If extensive decay is found in the tooth or the risk of infection is diagnosed, you may require a root canal treatment first. If there is not enough natural tooth structure to hold the crown in place securely, you might need a core or a post-and-core first. However, if everything is satisfactory, the appointment will proceed as planned. The procedure will vary depending on if your crown is made at your dentist or in another lab. Either way, the procedure can look like this:
First, your doctor with numb the natural tooth and gum surrounding it. Then, decay or old filling material is removed. The tooth is then filed down along the chewing surface and sides to make room for the crown to fit on top. Then the doctor will create the crown either from a picture or impressions. The doctor will check the crown’s fit and make adjustments if needed. Finally, the crown will be permanently cemented to your tooth.
Get a Dental Crown with California Dental Care
Dentistry has come a long way from just plain metal crowns. These days we offer a variety of options to suit every individual case. Whether you are after durability, strength, or the most natural aesthetic appearance, we can custom manufacture a crown to fit seamlessly into your smile. If you are interested in how a crown can benefit your smile, reach out to California Dental Care. Call us at (707) 535-8008, or click here to schedule an appointment.