Is There a Definitive Way to Determine if Crown Fits Properly?

I recently had all porcelain dental crowns installed on my four front teeth. When I floss two of them at the gumline, I can taste and smell a foul bacterial scent on the floss.

The dentist poked around with a dental instrument and says they fit properly, but I disagree. None of my other teeth (crowned or real) produce the odor, so something isn't right. He told me x-rays won't necessarily show whether or not they fit, so is there a definitive way (i.e., special type of x-ray, MRI, etc.) to determine if the fit is correct?

Doctor Answers 8

Crowns....Good Fit or Bad Fit

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Whether the crowns are a good fit or not BEGINS AT THE BEGINNING. When the dentist FIRST begins tooth shaping the margins must be placed so the biology of the gum tissue (gingival sulcus) is not compromised. Go too deep and the gum tissue will always be inflamed after the crowns are placed. A crown can be a good fit but be too deep in the gum and it will always be red and puffy.  If the preparation (shaping) of the tooth doesn't result in clearly defined margins which are recorded in the impression the crowns won't fit correctly. Then there is the responsibility of the dental lab. A good lab can't make well-fitting crown with a flawed impression. An inferior lab can't make a good crown from a good or bad impression. In the end it is always ultimately the responsibility of the dentist. Determining whether a crown fit is good is pretty simple. When in doubt it's always okay to get another dentist's opinion.

Dubuque Dentist

How Can I Tell if my Crown Fits Properly?

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Well done porcelain dental crowns ought to settle in and last for years with no more than minor issues. We always check the fit of any new crown we fit with an X-ray. Your dentist is correct that not all issues with the fit show on X-rays, but it is still the single most useful test to verify the fit. There are no other types of X-rays or MRI's that are helpful or pragmatic.

Often all porcelain crowns are actually bonded. This adhesion process is very technique-sensitive. If the edge of the crown is under the gum line, this can affect the adhesion process. Sometimes the gum irritation is not from a bad fit of the crowns, but from some extra cement left behind. This does often show on an X-ray. 

The most practical way to proceed right now is to request an X-ray. Check both the fit of the margin and check for any excess cement. You may need some time with the hygienist and possibly even be numbed so she can do some additional fine cleaning there. In our office our hygienist is trained with the laser. The laser is sometimes an exceptional tool to help improve very fine or delicate gum problems.


You can determine the fit of a crown.

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Yes, you can determine if a crown fits well.  First, by feeling the margin (where the crown fits the tooth) of a crown with an instrument.  Secondly, by an x-ray.  These two things will give the diagnostic information needed to determine if a crown fits well.

Kimberly Johnson Genc, DDS
Newport Beach Dentist

What is the cause of odor around my new crowns?

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 An x ray will show if there is a gap between the crown and the gum. If there is an odor around these two new crowns at the gumline, there are some plausible explanations besides the fit of the crown. The odor you find when you floss in this area could be caused by decaying food or the presence of bacteria under the gum.  I would have my teeth cleaned.  Have the dentist check for periodontal pockets around the teeth.

Flush the gum area with a waterpik with hydrogen peroxide or dip your tooth brush in the peroxide and brush that area and see if the smell improves or  goes away.  Hope these suggestions are helpful and i am sorry you have to go through this after having new crowns on your front teeth!  Make sure your dentist resolves this problem. Crowns are expensive and you should be happy with yours!

Robert Fields, DDS
Van Nuys Dentist

Smelly Crowns

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I always feel that the patient is a great source of information. If you know there is a bad odor from only two of the crowns I would go back and ask the dentist to check again. All porcelain crowns are VERY technique sensitive, even the smallest misalignment will cause more problems than traditional metal based crowns. Call ahead and say that you will need an x-ray on the tooth. That way there is a chair set aside for you and the dentist is not rushed. Early morning appointments are often better too.

Good Luck!

Annalee S. Kruyer DDS
Las Vegas Dentist

Xrays and dental explorer

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Taking an xray of the crowns should help, as well as a dental explorer (the metal pick that dentists use all the time). If the xray looks great and the explorer feels smooth, then the problem is likely something else. Try dipping toothbrush bristles in hydrogen peroxide and scrubbing the area 2 times per day for a week and see if things change.

A $4000 MRI is not really a good choice here, and the details given aren't precise enough to determine fit.

Checking the fit of a crown

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Checking with an explorer all around the crown is the best way to catch an opening between the margin of the crown and your own tooth. But you can always use x-ray as a help to determine if there is any gap.Tthe odor might be coming from uncleaned cement left after the veneers or crowns were cemented. Ask your doctor to use loops and interproximal saw and polisher and remove all the extra cement.left interproximally I am sure that's what is causing the odor.

Kate Sahafi, DDS
Orange County Dentist

There are several ways to determine if crown fits properly

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First, the crown has to fit perfectly over the tooth so that its margins meet the margins of the tooth preparation. Once the crown is "down" on the tooth, the contacts between the adjacent teeth should be adequate: floss should snap on either sides without breaking and without just sliding through. A quick snap is indicative of good contacts.

Lastly, the bite (occlusion) should be checked. The crown should not modify the feel of the existing bite. If there are any interferences, which make the crown feel "high", that should be adjusted.

Anca Bazile, DDS
New York Dentist

These answers are for educational purposes and should not be relied upon as a substitute for medical advice you may receive from your physician. If you have a medical emergency, please call 911. These answers do not constitute or initiate a patient/doctor relationship.