Need a dental crown? These appliances, sometimes called tooth crowns, are one of the most common dental services today. They serve to protect the sensitive inside portion of your teeth.
There’s a lot of misinformation and confusion out there about dental crowns. Can I glue a crown back on myself? How do I take care of my crown? What kind of crown should I get?
If you or your child needs a dental crown, what should you expect? What are your options?
By the end of this article, you’ll understand everything about crowns.
What is a dental crown, and why do I (or my child) need one?
Dental crowns cover teeth after damage or cosmetic issues. They’re used for several reasons—and you don’t always need a root canal to have a crown.
A dental crown is a cap made of inanimate material (typically porcelain or gold) shaped to look like and fit onto a tooth so that the inside of the tooth isn’t exposed.
Traditional caps cover the entire portion of your tooth, beginning at the gum line. Other options, called “3/4 crowns” or “onlays”, don’t cover the whole tooth.
Common reasons you might need a crown (sometimes called a tooth cap) include:
- Blunt trauma that actually breaks teeth
- A root canal in which the tooth is opened and the nerves and infection from inside the tooth are removed
- A deep cavity
- A large filling that leaves too little tooth material (on fillings, a good rule of thumb is that a filling ⅔ of the tooth wide or larger needs a crown)
- The need for a bridge (crowns are placed on the two or four teeth on either side of a missing tooth to connect the dental bridge)
The purpose of a dental crown is to protect the inside of your tooth from future fracturing. Particularly for broken or greatly damaged teeth, crowns can improve your ability to chew and bite down on food.
Your child may need a crown on a baby tooth if:
- S/he has a cavity but has trouble keeping up with good hygiene and a cavity-reversing diet. For children at high risk for further tooth decay, a crown may be preferred to other corrective procedures, especially if they would require general anesthesia. If your child has behavioral or mental issues that make normal dental care difficult, consider using dental crowns on baby teeth to protect them from cavities.
- S/he has a cavity that can’t be filled. Root canals aren’t often necessary for baby teeth. For very decayed baby teeth, crowns can hold the tooth together until the adult tooth comes in.
Crowns are not the same as living teeth. Let’s look at the differences between teeth and crowns and everything else you need to know about dental crowns.
What is a dental crown procedure? Is it painful to have a crown put on your tooth?
Whether you’ve had a root canal or need a crown for other reasons, you’ll usually need two visits for the dental crowns procedure.
So, what is a dental crown procedure?
During your first visit, your dentist will use a numbing agent around the tooth that needs a crown. Then, s/he will file down your teeth so that the crown can fit properly. Finally, s/he will take an impression of your reshaped tooth using putty or paste.
You’ll also get a temporary crown that day which lasts 2-3 weeks until your second appointment. Once your dentist receives your manufactured crown, you’ll come back for a second visit to have the new crown put on. You may or may not be numbed for that process.
Getting a crown isn’t a very painful process, either at the dentist or once you get home. The most pain you should expect is a little tenderness in your gums.
Some dental offices use in-house crown manufacturing, allowing for only one visit rather than two separate ones.
The Differences Between Caring for Crowns and Caring for Teeth
Unlike crowns, teeth are living organisms. Teeth:
- Are constantly remineralized and demineralized throughout every day (this happens at different rates depending on what you eat and your dental hygiene habits)
- Wear at a consistent rate (about 10 microns per year)
- Can be stained
- Can be whitened (either extrinsically or intrinsically)
That’s because they are alive, just like any other tissue in the body.
Dental crowns are foreign objects used to protect the living part of a tooth when it becomes exposed. Depending on the material, a crown may or may not wear at all.
Its color doesn’t change, it can’t respond to blood flow or nerve activity, and it can’t be remineralized or demineralized—because it’s just not alive.
When you get a temporary dental crown meant to last just a few weeks, you can take care of it by:
- Chewing on the other side of your mouth from your temporary crown
- Not eating sticky or hard-to-chew foods
- Sliding, rather than lifting, floss from between the crowned tooth on either side
Fortunately, the way you care for a permanent dental crown is the same way you care for your teeth. After the first hour and a half or so after a permanent crown is put on, it becomes a part of your dental structure.
Crowns need regular brushing and flossing. The inside of the tooth they protect does best when you support your oral microbiome. This means following good dietary and hygiene practices to help your mouth’s environment stay balanced (like tongue scraping, rinsing after eating acidic foods, using oral probiotics, etc.).
Why? Because crowns aren’t just cosmetic. You get a crown to protect your teeth from fracturing. Fractures are more likely when bacteria gets in the tiny space (called the margin) between tooth and crown. These bacteria have the potential to break down the living tissue inside.
If the tooth under your crown becomes decayed, the crown probably won’t stay on much longer. Preventing decay under your crown is one key to keeping your dental crowns as long as possible.
In addition, crowns can become a little tricky over time because of how they wear (or don’t wear) and other factors that impact a crown’s fit on the tooth.
FAQs About Dental Crowns
What kind of crowns are available, and which one is the best?
There are three basic types of crowns your dentist might recommend:
- Metals: Dental gold is the best metal option, but some dentists also use other alloys such as chromium or nickel.
- Porcelain: An all-porcelain or porcelain-fused-to-metal crown is the go-to option for visible teeth that need crowns.
- Resin: Crowns made entirely from resin are a cheaper option than the others. But they’re cheap for a reason: these crowns often crack and/or need replaced a lot sooner.
What is the best type of dental crown? Porcelain crowns are most suitable for front teeth and gold crowns can be used for teeth in the back of the mouth.
At the margin of any crown, bacteria can get in to cause a cavity. A benefit of a gold crown over porcelain is that the size of the margin (called the “discrepancy”) is much smaller with gold.
My patients with gold crowns have a discrepancy of about five microns. Porcelain crowns leave an open margin of about 200 microns that can be detected by a sharp instrument. The smaller the discrepancy, the less space dental cement is needed to fill and the less chance you’ll get a bacterial infection.
Another reason I recommend gold crowns when possible is that porcelain doesn’t wear at all over time—but your teeth do. Dental gold, though, wears at the same rate as your teeth: around 10 microns per year.
The wear rate of your dental crown matters for two reasons. One, when your living teeth wear down but your crown does not, as with porcelain, the margin between tooth and crown will continue to increase. The larger your margin, the more space bacteria have to get in and cause further infection or decay.
Two, your bite naturally changes over time as your teeth wear. A crown which doesn’t wear will disrupt your bite as your actual teeth change in size—think of how it might feel to have one longer tooth when you bite down.
If your child needs a crown, your dentist may recommend another type of metal crown: stainless steel. Stainless steel crowns can be made to fit baby teeth and easily come off with the tooth when it falls out.
I understand that many people don’t want gold crowns, or other metal crowns, for cosmetic reasons. Many dentists don’t even offer gold crown options!
Porcelain isn’t toxic, unlike common filling materials such as amalgam (mercury). It may cause some issues decades down the road as the tooth it’s on wears down, but it’s not a dangerous option by any means.
What issues could you eventually have with porcelain crowns? The major drawback of porcelain is that, unlike gold, it doesn’t wear down. As I explained above, this may open the door for further tooth decay as your margin expands to allow bacteria inside.
You’ll also need to replace a porcelain crown within 15-20 years. It may sound like a long time, but gold crowns last much longer (between 30-50 years). Especially if you’re looking at a dental crown for a back tooth, go with gold if you can to avoid having to replace it down the road.
Porcelain-fused-to-metal crowns may have a dark line around the gumline of the tooth they cover. These less expensive alternatives to porcelain crowns may not be as preferable from a cosmetic standpoint.
If you opt for a gold crown, you’ll need to find someone who specializes in dental gold. It’s actually easier to manipulate than porcelain but does require a different technique.
How much does a dental crown cost, and is there an alternative?
A good quality porcelain crown will probably run between $900-1600. A gold crown tooth adding about $100 to the total cost.
The price of a crown varies by location. Seeing a general dentist versus a prosthodontist who specializes in these sorts of items will also impact cost (general dentist crowns are less expensive).
Quality matters here. Some dentists will charge less ($600-800) but get crowns from labs overseas from places like the Philippines. Unfortunately, this often results in contaminated products. Many of these factories also use generic materials rather than brand-name ones that have consistent results over years.
Ask your dentist or dental assistant for the brand name of the dental crown you’ll be getting (I personally use EMax and Bruxer). A good lab will provide that name and you can use it to do your own quality research online.
Bonus: brand names keep their colors the same over time, unlike generic varieties. I keep records of patients’ crown colors and can duplicate them over time.
The cost of a crown is the number one question I get from patients, and I know it’s an important one to answer. Even though the dollar amounts may seem large, a crown is vital to your dental and oral health. If you need a crown, you risk long-term damage or infection the longer you wait to get it.
After a root canal, I tell patients that they can wait up to six months to get a crown if they’re eating well and following good hygiene. More than that is not a good idea.
Can I just wear my temporary crown forever?
When you go to the dentist for a first crown appointment, your dental assistant will fit a temporary crown. You’ll wear it about two weeks, until the permanent crown has been manufactured and delivered. Depending on the quality, some temporary crowns could be worn for several months or longer.
However, no, you shouldn’t just settle for the temporary crown.
Why? Because of the type of materials used for temporary dental crowns, they will change shape. This allows for shifting of other teeth, collect bacteria, and even possibly allow gum bleeding or inflammation.
My crown fell off. Do I have to go back to the dentist or can I glue it back on myself?
It happens—crowns sometimes don’t stay on, and it’s not always possible to see the dentist within the first few hours. While there is a good temporary solution, you will still need to see your dentist to have the dental crown permanently reattached.
The best thing to do for a crown that falls off is to buy over-the-counter temporary dental cement, available at most drugstores or online. These bonding agents are temporary, but can definitely hold on a crown for a few days or up to a week before you can get into your dentist.
The worst thing to do (which is, unfortunately, incredibly common) is to use Super Glue. I see it often… A wife keeps glue in her purse for the occasional need, and her husband will rifle through to find it and glue a crown back on his tooth to save a costly trip to the dentist.
I once had a patient share with me that Super Glue was better than Krazy Glue for putting a crown back on. Obviously, he’s had some experience differentiating between the two.
I’ve had patients try Super Glue, emery boards, and even power tools to reattach their crowns. As amusing as it sounds, using any of these methods to reattach a crown will lead to much more expensive dental work.
It is true that cyanoacrylate, the generic name for Super Glue and Krazy Glue, is used by physicians for wound repair. In fact, cyanoacrylate bonds very well to surfaces that are moist and non-porous.
Sounds perfect for that dental crown that keeps coming out, right?
Unfortunately, that notion is wrong and here’s why: The crown is a non-porous surface and can be moistened, but the tooth, despite being very moist, is also very porous. Therefore, the adhesion (glueing) between the two is negligible and will not last.
The real danger is forcing the cyanoacrylate down and killing the inside of the tooth. This will ultimately lead to the need for a root canal or even the loss of the tooth due to resorption. It’s also toxic to the gums and can cause necrosis, or tissue death.
The Bottom Line: Don’t use anything but temporary dental cement to reattach a crown that falls off. Then, get to your dentist as soon as possible to have it reattached.
How does my crown stay on?
Did you know that your crown actually doesn’t stay in place because of adhesion (aka, glueing surfaces together)? Dental crowns remain in place for years by a process called mechanical retention.
Mechanical retention is best explained like this: Imagine placing an identical, straight drinking glass over another identical glass. Pick up the upper glass and the one below comes with it, and the two “stick” together as you lift the top glass.
Now, try that with two identical bowls stacked face down on top of each other. It’s impossible to pick the bottom bowl by lifting the one placed on top. This is a simple example to explain how mechanical retention works—and doesn’t work.
A dental crown is made to be at an angle of 3% or less to the tooth surface—more than that, and, like the bowl example above, you’ll find that nothing holds.
Correct mechanical retention allows a crown to stay on indefinitely, especially if you practice good dental hygiene and avoid the worst food for crowns.
The “glue” your dentist uses is luting cement, made from zinc oxide and eugenol. It simply prevents saliva from getting into the margin (the space between tooth and crown); It doesn’t hold the tooth to the crown.
Parallel walls make the difference—a crown with a huge taper (known as “teepee prep”) will fall off. You need near parallel walls on all four sides. I describe the way this looks like a mesa: a flat-topped hill.
Why would my crown fall off?
Once a dental crown starts moving, it breaks the cement and will fall off because it’s retained via friction, and movement disrupts the friction. So, if that crown keeps falling off, it’s not due to a lack of adhesion—it means your tooth underneath isn’t the right shape for mechanical retention.
Dentists don’t actually use glues; we use cement to prevent saliva from seeping between the crown and tooth. This prevents tooth decay.
The shape of the tooth underneath and the tightness of the fit keep the crown from falling off.
How can I prevent my crown from falling off?
Some of the ways to prevent a crown from falling off aren’t things you can control. For example, a car accident or other trauma can make you clench your teeth and jam them in such a way that mechanical retention is disrupted. Oral surgeons sometimes pop off fillings when they’re removing a nearby tooth. In addition, poorly made crowns don’t like to stay on forever.
However, there are steps you can take to prevent your dental crown from falling off, too. The most important of these is to avoid or very carefully eat sticky foods.
To illustrate this point, I should share that when I am removing a crown in my office, I use jujubes!
First, we soften a jujube in warm water. I place it over the crown, requesting the patient to bite down. Once the jujube cools, I instruct them to open again. This is the most effective (and inexpensive) way to remove a crown.
The same applies to a dental crown you may not want to remove. If you make a habit of eating sticky foods, you should be very cautious chewing with a tooth that has a crown.
Take good care of your teeth and crowns by:
- Brushing and flossing properly
- Eating a lot of plant-based, nutrient dense foods
- Learning to breathe through your nose
The same things that are good for your teeth are usually good for your crowns.
Can I whiten my crown?
Porcelain crowns can’t be whitened because they aren’t living tissue. The good news is that they also can’t be stained like living teeth, either.
When you initially get a porcelain crown, your dentist and lab match your current tooth color (which, by the way, isn’t really “white”). However, this can become somewhat problematic if your teeth change color significantly over time.
If you want a whiter crown (or darker, in fact), the only solution is to go to the dentist for a new crown.
How long do crowns last?
Assuming the crown is properly done, a porcelain crown lasts 15-20 years, while a gold dental crown can make it 30-50 years.
You may need to have a crowns’ fit readjusted in that time if it falls off. Even the best porcelain crowns can’t last more than about two decades.
How do I best take care of my crown at first? What about as time goes on?
Many people have a misconception that crowns must be “babied” for the first several weeks (don’t chew on them, be super gentle with brushing, etc.).
While these tips are great for your temporary crown, they aren’t necessary once a permanent crown is attached.
In reality, what I tell my patients is this: Wait at least 60 minutes (I give them an exact time) before eating, brushing, or flossing. After that, your permanent crown will function like the rest of your teeth.
You would be surprised how many people want to go straight home and floss around the dental crown, but this doesn’t give dental cement a long enough time to set.
Over time is when porcelain crowns become more problematic because they wear at a different rate than the crown. Trauma, disease that increases inflammation, or a poorly balanced oral microbiome can also impact the fit of your crown.
If you begin to feel a crown shifting or experience pain in that tooth, visit your dentist to see if you need a replacement or reattachment.
What’s the difference between dental crowns and veneers? What about crowns and dental bridges?
Dental veneers only cover the front of your tooth, while crowns encase the entire tooth. Veneers are thinner than crowns and require less grinding down of the tooth to fit correctly.
Most of the time, people get dental veneers to improve the color or appearance of visible teeth. But veneers don’t actually protect your teeth the same way a dental crown does.
Dental bridges use a fully prosthetic tooth (or teeth) to fill in a gap between two existing teeth.
When you get a bridge, the teeth on either side of the gap must be covered with a crown. If either of those teeth are particularly small or weak, your dentist may opt to crown two teeth on the sides of where the prosthetic tooth/teeth go.
Final Thoughts on Dental Crowns
Dental crowns are used when the tooth surface is altered and where the inside of the tooth needs protection from infection and breakage. This happens in many cases including root canals, tooth breakage, large fillings, and more.
Children may need crowns to protect baby teeth if they have issues that prevent them from taking good care of their teeth. Baby teeth may also need crowns to protect a cavity too large for a filling, until the adult tooth comes in.
Contrary to popular belief, crowns and root canals don’t always go hand-in-hand. Just because you need a crown does not necessarily mean you also need a root canal.
Unlike living teeth, a dental crown is an inanimate object used to protect living teeth. The way you care for them is essentially the same as teeth—by brushing, flossing, etc. But crowns can’t be whitened, mineralized, or stained.
Well-made crowns can last for up to 50 years, in the case of gold, or up to 20 years with porcelain. Grinding teeth (bruxism) shouldn’t cause a good crown to fall off. But trauma, eating sticky foods, and other experiences may loosen the mechanical retention holding your crown in place.
If your dental crown falls off, schedule an appointment with your dentist immediately. You can purchase dental cement over the counter that will temporarily hold the crown on until your dentist can reattach it for you.
Do not use Super Glue or any other adhesives to reattach your crown on your own. These will lead to much more serious problems down the road because of toxicity and actually don’t work long-term.
What other questions do you have about crowns?Read Next: Can I Whiten My Crowns?