How to tell if your dental crown needs replacing.

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Signs to look for that suggest your dental crown should be replaced.

Your dental crown should provide durable, lasting service (How long?). But just like with all other kinds of dental restorations, a point is sometimes reached where it can no longer adequately serve its intended purpose and function. And if so, it will require replacement. This is true of all kinds of dental crowns, all-ceramic, porcelain-fused-to-metal, and even all-metal (i.e. gold) ones.

Why your identifying problems is so important.

Recognizing the signs that your crown’s lifespan may be coming to an end can play an essential role in maintaining your oral health and avoiding complications. Additionally, being able to identify when your crown requires replacement in a timely fashion can save you from needing more extensive and costly dental work on down the road.

So, how can you tell if your crown is deficient or failing?

That is the subject we cover on this page. Just read on …

Signs that may indicate that your dental crown needs replacement.

Watching out for any of the following signs and symptoms can be important in identifying when your crown should be replaced.

• Porcelain cracks, chips, or fracture.
• Restoration wear and tear.
• Gum recession / Dark line.
• Discoloration / Shade issues.
• Loose or lost crowns.
• Tooth decay.
• Pain or sensitivity.

If you notice any of these issues, it will take an evaluation by your dentist to confirm your concerns. During their examination, they may even discover additional problems that you were unaware of.

Once they have collected all of the information they need, your dentist can then make a recommendation about whether or not your crown needs to be replaced.

FYI: Two related topics we cover on this page –

• Reasons why dental crowns aren’t repaired.
• Things you can do to prolong the lifespan of your crown.

1) Crowns that show cracks, chips, or have fractured.

While it’s rare that a metal dental crown will crack, fracture, or chip, a ceramic one may.

What you should look out for.

• Under the right lighting conditions, you may be able to identify minute cracks and craze lines that have formed in your tooth’s ceramic surface, especially if they have picked up stains.
• Chips or fractures usually result in a rough or sharp defect that’s often first detected by your cheek, lip, or tongue. Because a piece is missing, persistent soft tissue irritation or food impaction problems may be noticed. With front teeth, the lost portion of porcelain may create a cosmetic emergency.
• Full-thickness fractures can be more catastrophic. A through-and-through crack will result in the loss of the crown’s seal over your tooth. (Signs can include hot and cold sensitivity or sensitivity to sweets.) Once cracked, partial or full loss of the crown from your tooth may occur (sharp edge and food-impaction problems may be noticed).

A broken porcelain dental crown.

Further details about what you may notice with different kinds of crowns.

a) All-ceramic dental crowns.

All-ceramic crowns may develop cracks, chip, fracture, or even break entirely, particularly when subjected to heavy biting forces, teeth clenching and grinding (bruxism), or accidental impact. (This potential varies among dental ceramics, some are considered “high-strength.“)

Since the full thickness of these crowns is ceramic, crack formation has the potential to involve the full thickness of the restoration. In cases where it does, a pathway will then exist through which bacteria can pass, possibly causing tooth decay underneath the crown. (A location where it can be difficult to detect.)

b) Porcelain-fused-to-metal crowns.

The core of a PFM crown consists of a thin metal substructure that fits snugly over the tooth. A layer of porcelain is then fused to this metal cap, giving the crown a natural tooth-like appearance.

Cracks and craze lines that develop in this outer porcelain shell may significantly compromise its strength and result in chipping or fracture. However, the seal of the crown over its tooth is not usually lost.

Possible repair options.

Crown replacement is usually the only satisfactory solution.

• While a dentist may attempt to patch a cracked or fractured ceramic crown, the long-term outlook for this type of repair is usually poor (both in strength and appearance).
• With all-ceramic crowns, it would be impossible to know if a crack fully penetrates the thickness of the crown and if the patch can effectively block the infiltration of bacteria.

2) Crowns that show signs of wear.

Even though dental crowns are generally considered the strongest and most durable kind of dental restoration, signs of wear and tear can develop over time. This is especially true for people who have a habit of bruxing (grinding their teeth). This constant back-and-forth, tooth-against-tooth motion can abrade a crown’s surface or opposing teeth.

What you should look out for.

a) With metal crowns.

All-metal crowns (or porcelain-fused-to-metal crowns that have a metal chewing surface) may wear down to the point of developing a “perforation.” (A hole through the crown that exposes a portion of its tooth underneath.)

• Because the crown and exposed tooth surface wear down in unison, the edges of the perforation may be so smooth that you can’t feel the opening (like with your tongue). However, if the perforation is of any size, you should be able to see it (if you have a way of visualizing that aspect of your tooth).
• The exposed tooth surface may have thermal sensitivity (like in response to hot and cold foods and beverages).
• Of most concern is that bacteria can infiltrate through the perforation and underneath your crown, possibly causing tooth decay. Sensitivity to sweets or the formation of a deepening hole may indicate this.

A perforated gold dental crown.

b) With porcelain crowns.

Over time, you may notice that the shape of your porcelain crown has changed due to abrasion caused by opposing teeth. (This potential varies among dental ceramics, some are considered “high strength.” See link above.)

As the ceramic wears thinner and thinner, its potential for cracking or outright fracturing becomes of increasing concern. With front teeth, the appearance of the worn crown may be objectionable.

c) Effects on natural teeth.

Instead of porcelain wear, a more likely scenario is one where the ceramic surface of a crown has seriously abraded the natural tooth it opposes.

This is because the crown’s porcelain surface has lost its glass-like glaze and therefore acts like sandpaper against opposing teeth. This is often due to the fact that the crown’s “bite” was adjusted (trimmed using a dental drill) but the restoration was not polished adequately afterward.

Possible repair options.

Crown replacement is usually the only satisfactory solution.

• A dentist may plug a crown perforation by placing a filling in it. However, the integrity of the seal created by this kind of repair is never as predictable or lasting as replacing the damaged crown.
• A dentist may attempt to patch a worn ceramic crown by placing filling material. But even if possible, the long-term outlook for this type of repair is usually poor (the patch frequently dislodges). Trying to patch worn ceramic restorations that have cracked or fractured also typically has a poor prognosis.
• In the case where the abrasive porcelain surface of a crown has worn opposing teeth, it may be possible for the dentist to polish the offending area. If not, the crown should be replaced.

3) Crowned teeth that have gum recession.

Despite their best efforts in maintaining proper oral home care, a person may find that over time the gum level on their crowned tooth has receded to a point where the edge of their crown now shows.

What you should look out for.

a) The exposed edge of your crown.

As gums recede, the edge of your dental crown (its “margins”) will start to show. This change is often of limited concern but when front teeth are involved, it can pose a significant cosmetic dilemma that can only be corrected by crown replacement.

When gum recession does occur:

• Dental plaque may tend to accumulate at the edge of your crown, therefore increasing your risk for further recession and even cavity formation. However, your access to the area for cleaning should be more than adequate to maintain your dental health.
• Despite that the recession has occurred, structurally and functionally your crown can be expected to continue to provide service for years to come. (Hence with crowns on back teeth the issue of a receded gum line is frequently just monitored.)
• Some people have a long lip line and therefore the exposed portion of their crowned tooth doesn’t show. If not, this issue is sometimes noted and periodically evaluated but otherwise ignored.
• The portion of the tooth’s root that’s become exposed may display sensitivity to hot and cold (like foods and beverages), air, or touch. This kind of sensitivity is usually easily treated.

b) A dark line at your gum line.

A major aesthetic problem that may develop with front teeth as their gum line recedes is the exposure of a dark line at the edge of their crown.

• If the tooth has a porcelain-fused-to-metal crown, the dark line is literally the metal edge of the crown that now shows.
• With all-ceramic restorations, the dark line forms because the crown’s luting agent (cement layer between the crown and tooth) has picked up stains.

A dark line has started to show at the edge of this crown.

In either case:

• You may start to notice the black line long before you realize your gums are receding or any portion of your tooth’s root has started to show.
• With PFM crowns, the line is not an indication of tooth or crown deterioration or damage. The same may be true with all-ceramic crowns. Both situations should be evaluated by your dentist.

Possible repair options.

Crown replacement is usually the only satisfactory solution.

Generally speaking, gum line recession and/or the development of a dark line at the edge of your crown are cosmetic issues. However, only an evaluation by your dentist can make that determination.

• In cases where tooth aesthetics are of limited concern (back teeth, people with lip lines where their front teeth don’t show), a decision may be made to just monitor the situation but not treat it.
• Sometimes a dentist will attempt a patch by placing dental composite (white filling material) over the exposed root surface and offending dark line but these kinds of repairs typically fail (especially cosmetically).

4) The shade of your crown doesn’t match well.

While not a failure in terms of function, you may seek the replacement of your crown because its shade doesn’t match well. We’ve dedicated an entire page to this subject and it explains why color mismatch issues may exist and what can be done to rectify them. You can find our page here:

What can be done if the color of your dental crown doesn’t match? Jump

5) Having a crown loosen or come off.

It’s not terribly uncommon for a crown to come off its tooth. And in a large percentage of cases, after a little checking and cleanup by your dentist, the restoration can be cemented back on. (Related page: How to temporarily cement a lost crown.)

However, and also in a large percentage of cases, having lost a crown or noticing that yours is loose can be an indication of an underlying problem, like tooth decay, tooth fracture, or poor crown design.

What you should look out for.

a) Crown looseness.

The fit of a crown on its tooth should be fixed and firm. If instead you detect some movement or shifting, evaluation by your dentist is required.

• Crown looseness may occur because the integrity of the crown’s luting agent (bonding, cement) is no longer fully intact. If that’s the case, the crown’s seal over its tooth has been lost and bacteria will be able to seep underneath it and possibly cause tooth decay.
• Another possibility is that the portion of your tooth that supports your crown has fractured and is loose.
• Either way, you have to expect that sooner or later things will give way fully and your crown will come off, no doubt at the most inopportune moment. (Related page: What to do if you’ve swallowed your crown.)

b) Crown loss.

• A crown may come off due to an associated dental problem. This can include tooth fracture or the presence of extensive decay. Obviously, any crown that comes off requires evaluation by your dentist.
• If your crown has a history of coming off repeatedly, it may be due to poor restoration design (poor resistance/retention characteristics). If your dentist feels they can make an improvement, they may recommend replacing your crown solely for that reason.

Possible repair options.

Crown replacement is usually the only satisfactory solution.

It’s important to understand that the fit of a dental crown on its tooth must be exact. If any tooth structure loss (like due to decay or fracture) has changed the tooth’s original shape (especially at its “margins,” the area where the edges of a crown rest on its tooth), the crown will no longer be able to create an adequate/predictable seal. And for that reason, your dentist will need to recommend replacing it.

6) Discovering an area of decay on your tooth.

Cavities can’t form on dental crowns but they certainly can on tooth surfaces that lie adjacent to their edge.

What you should look out for.

a) A dark spot or a hole in your tooth.

If you find that a dark spot, or especially a hole, has formed right at the edge of your crown, it’s likely a sign of tooth decay. Corroborating signs can be tooth sensitivity to sweets or possibly hot and cold stimuli (like food and beverages). If the decay advances, tooth pain may develop.

Possible repair options.

Crown replacement is usually the only satisfactory solution.

It’s the precise fit of a crown, especially at its edges (its “margins”), that creates its seal for a tooth. Anything that affects this relationship will compromise the seal, possibly allowing bacteria to infiltrate underneath the restoration.

In the case where a cavity has formed at the margin of your crown, the decay will almost always extend underneath the restoration too. And when your dentist removes it, the seal of your crown will be affected.

Decay at a crown’s margin frequently extends underneath the crown.

Placing a filling over the area might reestablish the seal. But this kind of patch isn’t as predictable or usually as lasting as making a new crown for your tooth.

7) Noticing sensitivity, pain, or other symptoms with your tooth.

Anytime you notice you have any pain, sensitivity, swelling, etc… associated with your tooth, your dentist should evaluate your situation. Noticing these kinds of signs doesn’t necessarily mean that something is amiss about your crown per se. But without question, your tooth and crown need to be checked out.

What you should look out for.

If you notice any of the following signs and symptoms, you should report them to your dentist.

• Sensitivity – Thermal sensitivity, sensitivity to sweets, or experiencing sensitivity to biting pressure, percussion, air, or touch.
• Discomfort or pain – The discomfort you notice might range from slight, to moderate, to intense. Be dull or sharp, constant or throbbing. It may be spontaneous or only triggered in response to stimuli, like biting pressure or hot or cold.
• Edema – Any swelling should be reported to your dentist for evaluation.

Possible repair options.

Crown replacement may be needed.

• Your dentist’s first goal will be to identify and treat whatever dental pathology has caused your symptoms, whether that involves something about your crown or not. (Related page: Why teeth with crowns sometimes require root canal treatment later on.)
• Once the pathology has been rectified, they will evaluate the current status of your crown to determine if it can still adequately meet its needed requirements.
• Sometimes a crown was never at fault but needs to be replaced as a result of other dental work that was required. (Related page: Does a crown need to be replaced after root canal treatment?)

Can a dental crown be repaired or does it need full replacement?

The short answer to this question is no, crowns can’t be repaired. At least not in the sense that they’re returned to their original fully intact status. Here’s why:

Crown repair requires high-heat conditions.

Whether it’s an all-metal crown or one that has a porcelain component, making a repair either requires soldering on additional metal or fusing on additional porcelain. Both of these processes require extremely high temperatures and, of course, that’s not possible to do in a patient’s mouth.

Removing a crown can be difficult and unpredictable.

A repair might be attempted if the crown could be removed from its tooth. But accomplishing that feat is much easier said than done. During the removal process, the crown or tooth might be damaged, possibly irreparably. And pretty much for that reason, crown removal isn’t attempted all that often.

Oral contamination may affect the repair.

Especially with porcelain repairs, contamination of the crown’s surface by oral fluids (when it was worn) can make the attempt or outcome of fusing additional porcelain to a restoration unpredictable.

Can dental crowns be patched?

A dentist may attempt a repair by patching a crown using standard dental restoratives (like white filling material or dental amalgam). The problem is that none of these materials can make a true bond with a crown’s surface (metal or porcelain). And that failure leads to two main problems.

1) Poor retention.

A patch added to the surface of a crown, especially in an area where chewing or biting forces are involved, usually dislodges at some point.

2) An unpredictable seal.

Unless a substantial seal can be created between the crown and its patch, bacteria will seep past the patchwork and infiltrate underneath the crown, and possibly start decay. (Detecting decay underneath a crown can be difficult, if not impossible.)

A dentist has no way of knowing how substantial the patchwork seal they have created is or how long it will last before being compromised. And that dilemma makes patching a crown a gamble.

3) Other considerations.

An added obstacle with patching ceramic crowns is that dental composite (white filling material) tends to wear down faster and is more likely to pick up staining than porcelain.

The bottom line –

With all other factors being of no concern (like cost, time spent, effort required, outcome certainty, etc…), it’s inconceivable that any dentist would ever recommend patching a crown over replacing it.

What can you do to prolong the life of your crown?

Once your replacement crown has been cemented, there are things you can do to be proactive in maintaining it and helping to prolong its lifespan. For example:

• Practice proper oral home care so gum tissue recession is less likely to occur – Dental plaque accumulation causes gum disease which can result in gum line recession. Brushing too hard, too vigorously, or using the wrong motion can cause gums to recede.
• Brush and floss to avoid cavities – Anywhere dental plaque is allowed to accumulate and persist on the surface of a tooth, especially for long periods, tooth decay may form.
• Avoid excessive biting forces – Heavy chewing forces, especially when hard foods are involved, create some risk of damaging dental crowns. Since the same thing goes for your natural teeth too, take it easy and avoid problems.
• Control your bruxism – A habit of clenching and grinding your teeth can lead to excessive crown wear or even breakage (the same goes for your natural teeth too). Control the effects of your bruxing habit by wearing a nightguard. Wear it some during the day too if you need to.
• Avoid high (acidic) and low (basic) pH foods and beverages and abrasive toothpaste – Over time, repeated exposure to these kinds of items and events may slowly degrade the ceramic surface of your crown.

If you think your crown needs replacement, what should you do next?

Contact your dentist.

If you’ve noticed any of the signs or indications we’ve discussed on this page, you should go ahead and contact your dentist. That’s because there’s very little you can do to further investigate your crown, much less rectify any problems. You need the attention of your dentist.

Make sure to ask about other possible options.

If your dentist does recommend restoration replacement, ask them to include the pros and cons of other types of dental crowns in their discussion about what kind to choose. Different kinds of crowns excel in different ways and choosing the right kind can help you avoid the same problems you’ve experienced before.

If you’d like to educate yourself a little bit so you know what kinds of questions to ask when you discuss things with your dentist, read this page:

What’s the best kind of crown for your tooth? – Factors to consider. Jump

That’s it for our coverage of this topic. Scroll on down a few lines to see our ‘What’s Next?’ menu. It lists other pages on our website that discuss dental crown issues. Thanks for visiting.