Expert: Frederick R. Liewehr DDS, MS, FICD - 12/14/2004

Question
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Followup To
Question -
HI, I'M 50. Two years ago I went to a newish dentist and he sent me to an endo for my first rc. He said, "have the RC then I'll finish it up." The endo said, after the therapy, "I can put a silver filling in it ; they last a very long time" so I figured I was finished w/that tooth. Then my face swelled for a week. My dentist seemed annoyed but never mentioned the lack of that crown he had suggested?
Now , the uncrowned tooth often has a slightly uncomfortable feeling while chewing certain foods (not temperature sensitivity). It doesn't hurt when I tap on it. Is it too late or should I go to my dentist asap for a crown? I don't have a toothache...yet. I just don't want it to fracture. thanks.
ps Sorry; it is the #3 tooth BACK from the top front tooth.
Answer -
Hi Suzy,
    Unfortunately, there is no way I can tell you what is causing your discomfort without seeing and examing you. Too many things can produce the same symptoms.
    I'll give you a couple ideas, though. A silver amalgam, properly done (what we call "shoeing the cusps", meaning completely covering the surface to hold the tooth together) can provide a wonderful, long-lasting restoration for your tooth. Unfortunately, many dentists do not properly design these restorations, and they do not provide the protection you need following root canal therapy. I cannot judge that without seeing it. So, it is not the material per se, but how it is placed.
    As for your swelling and so forth, that sounds like what we call a "flare-up", which is a poorly defined entity, other than it means you have to go back to the dentist unexpectedly. Don't laugh, that is actually how it is operationally defined in many studies. It is probably the result of bacteria causing a problem multiplying after treatment, for a short while, until your body's defenses get them under control. Usually, after the incident, everything is OK. Happens in about 5% or so of patients.
    The slight discomfort, what patients call a "different" feeling, sometimes never goes away. Like any surgical procedure, following root canal therapy you might return to 990 or 95% of what you were before, but never 100%. I sure know that from personal experience!
    On the other hand, it could indeed mean that your tooth is fractured. Once the pulp, or "nerve" is gone, you can no longer get that sharp toothache pain from cold or anything else, but you can get a dull pain from the fibers around your tooth.
    If you are getting that pain, your tooth may already be fractured, so it may be too late. On the other hand, the slight discomfort may simply mean that your filling is too "high", so you are constantly hitting it and making it sore. There is really no way I can tell those things without seeing you. Your endodontist would really be the person who should see you. Just tell him you have this residual discomfort and ask him to examine you and figure out what is causing it.
     Good luck, and Merry Christmas.

Dr. Liewehr

REPLY; THANK YOU!! You've said it may be too late as in I may need an extraction? But, the following says a crown CAN FIX a fractured tooth:
WHY DOES MY TOOTH NEED A CROWN ?

"As teeth are filled and refilled over the years, they reach a point where they can only be restored by a full coverage crown. (mine was filled once, decades ago). The remaining tooth structure will no longer support a large filling. Such a filling must be supported by the tooth; a crown supports the tooth itself. The most common indications for a crown are:

         1) Teeth with fractures ***

         2) Cracked teeth sensitive to cold and sugar  

         3) Teeth with large multi-surface fillings.
The filling is extremely small in this root canaled tooth. He drilled through the tooth then removed the nerve, finishing with the filling 2 years ago. You'd not see anything during an exam; maybe an xray would show something. So my question is: IF there is a SMALL fracture that causes this SLIGHT discomfort w/chewing, COULD a crown fix that permanently? And was I "supposed" to get a crown (3rd tooth from the front on top) after the crown? He said, "after the RC come back and I'll finish it up for you." thank you!!  

Answer
Hi Suzy,
    A crack is not a fracture in dental terminology, Suzy. A crack, as used in "cracked tooth syndrome", means the dentinal equivalent of a green-stick fracture in a child: damaged but not completely fractured, not "split" in other words. A fracture, as in a root fracture, means the root is completely fractured through and through. A cracked tooth can usually be saved if the crack is above the gum line, and a crown is placed to hold it together so that the crack does not become a fracture and actually split the tooth. If that happens, the tooth must be removed because bacteria in your mouth would travel down the fracture line into your jaw bone and cause an infection. The piece you quote probably was referring to a crown fracture, which means a piece of your crown broke off. It does not mean a root fracture, which is what I was referring to. Confusing, isn't it?
     Cracked tooth syndrome causes pain to biting and cold because the crack opens somewhat when you bite, and the cold then irritates the already inflamed nerve inside the tooth. Once you have the root canal, the nerve inside the tooth is no longer present, so you do not get those symptoms. Any pain would come from the nerves in the bone. If you only had a cracked tooth, the problem would be above the bone, in the crown of the tooth, not down the root, so if the tooth were endodontically treated, you would not have pain on biting. If the tooth is fractured, however, you would have a periodontal problem down the root, and it would be a little sensitive to biting. That is why I mentioned the possibility of a fractured root.
    Once the root if fractured, it is too late to place a crown. The crown is to PREVENT the fracture, not to fix it.
    If the tooth involved is the third tooth, that would be what is variously called a canine, cuspid, or eye tooth. It is the longest, pointiest tooth you have. Those teeth usually do not require crowns. If you are talking about anything farther back, posterior teeth should be crowned to prevent fracture. On the other hand, your tooth may have been fractured prior to the endotontic therapy, and that could be what caused the "nerve" to "die" in the first place.
    So, I am not in the position to tell you for certain what problem you had or what should have been done. I hope what I told you is of some help. As I said, you need to talk to your dentist to find out what you should do now. Good luck.

Dr. Liewehr