Dental crowns and bridges are very common procedures performed in the dental office. Their general purpose is to restore a tooth or teeth back to full chewing function. Crowns and bridges are different in many ways, and because bridges involve the use of crowns, we will describe a single crown first.

What is a dental bridge?

Dental bridges replace missing teeth. Specifically, they can replace one tooth or a row of missing teeth.

As the name implies, this appliance literally “bridges the gap” in your smile. Dentists can create custom bridges that match the shade of your natural teeth.

There are different parts that make up a dental bridge:

• Abutments are the structures that support your dental bridge. While the term often refers to natural teeth, it can also refer to tiny connector posts used in dental implant-supported bridges.
• Pontics are the artificial (false) teeth that fill in the gap left behind by missing teeth.

Depending on your situation and the type of bridge you receive, your bridge might consist of one or more abutments and one or more pontics.

Types of dental bridges

Dentists use different types of bridges based on your oral health goals. The main four types of dental bridges include:

1. Traditional dental bridge. This is the most common type of dental bridge. It consists of dental crowns (caps) on both ends with pontics (artificial teeth) in between. A dentist bonds the crowns to your natural teeth (abutments) on either side of the gap, and the artificial teeth (pontics) fill in the space between. Dentists use traditional dental bridges when you have healthy natural teeth on both sides of the gap.
2. Cantilever dental bridge. A cantilever bridge is similar to a traditional bridge. But there’s only a crown on one end, not both. So, when your dentist bonds the bridge onto your abutment tooth, the artificial tooth (pontic) “hangs over” or extends across the gap. Dentists use cantilever bridges when you only have natural teeth on one side of the gap. Due to their design, cantilever bridges aren’t as strong as traditional bridges.
3. Maryland dental bridge. A Maryland bridge (or resin-bonded bridge) uses metal wings instead of crowns to secure your bridge. A dentist bonds the wings to the backs of your neighboring teeth to hold your bridge in place. Dentists typically use Maryland bridges to replace front teeth. These appliances aren’t strong enough to withstand the chewing forces of back teeth.
4. Implant-supported bridge. An implant-supported bridge is similar to a traditional bridge, but it rests atop dental implants instead of natural teeth. Dental implants are small threaded posts that replace missing teeth roots. Before attaching a bridge to dental implants, your implants must fully integrate (fuse) with your jawbone. This process takes three to six months on average, but it can take longer depending on your situation. Dentists can use implant-supported bridges when you have three or more missing teeth in a row.

To determine what type of bridge you need, a dentist will consider several factors, including:

• Your age. (Dentists typically don’t place bridges in children.)
• How many teeth you’re missing.
• The size of the gap.
• The condition of your teeth next to the gap.
• Whether you have natural teeth on both sides of the gap.
• The overall health of your teeth and gums.
• Your personal preferences.

What is a Crown?

A crown, also referred to as a cap, is a dental restoration that covers the entire tooth, replacing its outer layer of enamel with a new material. A crown is contoured and sized similarly to a natural tooth, and they come into contact with the opposite tooth in a normal way, allowing for food to be chewed properly. In general, a crown should feel like a regular tooth when it comes to function. Depending on the material chosen for the crown, it also can look like a perfectly natural tooth.

What are Crowns Made From?

Crowns can be fabricated out of many different materials, including plastic, various metals, porcelain, or a combination of these. The different materials serve different purposes and offer several advantages and disadvantages, as outlined by the chart below.

Crown type Commonly used for: Advantages:Disadvantages:

‍Plastic Temporary crowns while permanent crown is being made in a dental lab Very inexpensive Only last for a short period of time and cannot be a final restoration Full metal crown (typically yellow gold)Very back teeth that are short in height

• Require least removal of tooth structure
• High success rate over long term
• Most resistance to decay

• Metal appearance
• Not cosmetically pleasing
• High cost due to price of gold

Porcelain fused to metal crownCan be used for any tooth in the mouth

• Relatively natural appearance
• Good long-term success
• Strong

• Can show dark shading at gumline where metal is visible
• Appearance is opaque, unlike a natural tooth
• Porcelain can fracture

All PorcelainAny front tooth

• Most cosmetically pleasing appearance
• Looks most like a natural tooth

• Requires most removal of tooth structure
• Easily fractured by patients who grind their teeth

ZirconiaCan be used for any tooth in the mouth

• Has the appearance of a natural tooth, but slightly more opaque
• Good at blocking out the darkness of a discolored tooth
• Very strong, with extremely low possibility of fracture

• Newer material that does not have good long-term studies
• Can cause damage to the tooth it bites against

Why do Teeth Need Crowns?

A tooth needs a crown when it no longer is strong enough to withstand normal chewing function on its own. There are multiple reasons a tooth could require a crown to function properly:

1. Large decay – If a tooth has a large cavity, which has destroyed its enamel and dentin (the core structure of teeth), it will be too weak to hold a filling and chew properly. By removing the cavity, building it back up, and covering it with a crown, the tooth will be able to do its job again.
2. Large fillings – If a tooth already has a large filling that covers more than half of the tooth, the remaining tooth structure is too weak to withstand chewing forces for the rest of the tooth’s lifespan. By covering it with a crown, the tooth is given a better long-term prognosis.
3. Cracks – Tooth cracks are a very complicated diagnosis and could be the subject of an entire article on their own. For a tooth crack with a limited extent (meaning it does not extend into the nerve inside the tooth or down the root underneath the gums), a crown is the only way to keep the crack from progressively getting worse. Teeth are covered in a solid layer of enamel, which acts as a protective coating. If that layer of enamel is disrupted by a crack, it is no longer doing its job, and it must be removed and replaced. The crown functions as the new enamel, protectively covering the tooth just as the enamel did.
4. Root canal treatment – When a tooth has a root canal, the nerve and blood vessels are removed from the hollow chamber inside the tooth. This means there is no longer any nourishment to the tooth, and it quickly becomes dried out and brittle. This brittleness predisposes the tooth to cracking. Any tooth that has had a root canal needs to be covered in a crown to prevent it from cracking. Root canals are expensive, and it would be a shame to let one go to waste because the tooth was never covered and cracked, requiring it to be extracted.

What is a Bridge?

A bridge is a fixed partial denture: it is fixed (glued) to the teeth, it replaces some (not all) of the teeth, and it uses a fake tooth or teeth (denture) in the place of missing teeth.

A bridge is used to replace one or more missing teeth, when functioning teeth are available on both sides of the missing tooth.

The adjacent teeth, called retainers, are covered by the bridge in exactly the same manner as a crown covers a single tooth. The difference is that the bridge connects the crowns to a pontic (fake tooth replacement) in the missing tooth space.

In the case of one missing tooth, a bridge would be three units: one unit for each adjacent retainer tooth, and one for the pontic. Bridges can be made from all of the same materials listed above for crowns.

What are the Benefits of a Bridge?

A bridge is a quick way to replace 1-2 missing teeth. It does not require any surgery, and it is typically paid for by dental insurance as a covered benefit.

A bridge requires two visits to your dentist. During the first visit, the two adjacent teeth are prepared just as they would be for crowns. You may wear a temporary bridge or just two separate temporary crowns while the bridge is being made by a dental lab. At the second visit, the final bridge is fitted and cemented to the teeth.

What are the Disadvantages of a Bridge?

Because a bridge connects multiple teeth together, it cannot be cleaned as simply as separate teeth. It is necessary for you to use adjunctive oral hygiene tools to help you get floss underneath the bridge for adequate cleaning.

In short, it takes a little more work to maintain it, keeping it clean and cavity-free. In some cases, the adjacent teeth have no problems, so in order to make the bridge, healthy tooth structure must be removed.

What are Alternatives to a Bridge?

A bridge’s purpose is to replace one or more missing teeth. There are two other general options for replacing teeth. One is a removable partial denture, which as its name implies is taken in and out. It is not cemented to the teeth.

A removable partial denture rests on adjacent teeth and uses either a metal or plastic base to hold fake teeth in place. The other tooth replacement option is a dental implant. A dental implant is the most expensive tooth replacement treatment, and it gives the most natural result because it is anchored in the jawbone and does not depend on or affect the adjacent teeth.

How Do Bridges Work?

There are many things to know about a dental crown & bridge like it can cover up the gap of missing teeth. Because of missing teeth, the other teeth ultimately shift or turn from their original positions, forcing a bad bite. This disparity can also cause gum diseases and Temporomandibular Joint (TMJ) disorders.

Bridges get cemented to the neighboring space of your natural teeth. These teeth are called abutments and provide support to the bridge. 

To get crowns and bridges, you can select the material through consultation with your dentist, which relies upon the location of your missing teeth, their purpose, appearance, and price. Pontic or replacement tooth gets fixed to the crown that covers the abutments. A material like porcelain and ceramic match the shade of your natural teeth.

How Do Crowns Work?

A crown completely covers up an injured tooth. It also provides strengthens, enhances the appearance, shape, and position of teeth. When put on top of an implant, it resembles the form and function of your tooth. Crowns come in acrylic and additional metallic alloys. Since metallic alloys are much stronger than porcelain, they are advised for back teeth, whereas porcelain appears more attractive.

A crown is usually suggested when –

• To replace a large filling due to a small portion of the tooth is remaining.
• Protect a weak tooth or repair it from damage.
• The requirement to fill a gap.
• Plaster a dental implant.
• To enclose a discolored or misshaped tooth.
• Wrap up a root canal.

Avoid munching on hard food like ice or food that clings to your teeth like sticky candies to prevent harm to your new crown or bridge.

How Long Do Crowns & Bridges Last?