Question:
After 8 months on a tooth that had a root canal, the crown came loose and
under the crown there was a break in the seal going to the canal. So in
other words bacteria got into the canal and I now have to go through
treatment to clean out the canal again.The front canal is draining again.
Question. What went wrong with the original treatment? The tooth felt
good until just before the crown came loose. Was the cement or sealing of
the canal at fault, meaning poor mixing of the sealant or just that some
bacteria was left in the canal after the original treatment?
What needs to be done to get this tooth back to 100%? The dentist did
some tests and could not find any crack in the tooth.
Answer:
Lately I've begun hearing from endodontists that coronal seal is vital
to endodontic success. Supposedly, if the crown is not properly restored,
bacterial leakage will rapidly (in perhaps a few weeks) percolate down to the
apical seal. I can't discount this. But if we accept this, it certainly
doesn't reflect well on the sealing abilities of our root canal fillings ( a
subject recently discussed in the thread about Lightspeed). It also means for
our endo friends that there really are no endodontic failures--they are all
the fault of the restorative dentist!
The studies I read (at least two years old by now) gave a 3-4 month life to
the sealing ability of Cimpat/Cavit type temporary cement. It then went on
to say that 3-6 months later bacteria could percolate down the length of the
gutta percha, and contaminate the apical tissues again. The studies gave a
4-8 month life for the combination of temp. cement and gutta percha prior to
apical contamination and the need for re-treatment.
Potentially, the root could be cracked, the root canal treatment could have
been faulty (rather rare), there could have been some leakage somewhere on
the tooth where no one was able to detect it (this happens to the very best
dentists), etc.
The end result is that you either have a failed RCT or a cracked root. Most
often it is a cracked root. Cracks are often only detectible with high
magnification and staining (after extraction of course).
Your crown may have come loose due to decay, poor bite, weak cement,
contamination during cementation, cracked root, loose filling/build-up, or
just bad luck.
I doubt anyone can tell you why you are in the spot you are in now. the
point is that you need to find out what your particular options are, discuss
them and make a decision. My guess???? You will need an extraction. DON'T
BASE YOUR DECISION ON WHAT I JUST SAID!!!
One thing my dentist was afraid to do was permantently seal the root canal
and bond the crown on. He says he wanted to "leave the door open" just in
case he had to get into the canal again and retreat it. Perhaps not
permantly sealing it has caused me problems 8 months from the original
tratment. Should I ask him to seal it as it should have been done in the
first place? He seems conservative, but he has been in the business for
over 40 years!
