From: "Arturo R. García D.M.D."
To: "ROOTS" 
Sent: Sunday, August 10, 2008 7:34 AM
Subject: [roots] The Tale of a Doomed Tooth

This is a story about #8.  This was part of the treatment for a fm rehab
case.   I have a little extra time these days, but not enough to get into
putting all of the color photos together ;-).  Anyhow, if you follow the
numerical sequence of slides:

1. Patient presents with failing rct under a pfm bridge (maybe I will put
   the pictures together- you should have seen how ugly this thing was!).
   Nice fistula present on facial.
2. Start of rct re treat- instrument and debride and load up with CaOH for 3 weeks.
3. 3 weeks later fistula gone.  Final fill.  Not too bad, but perhaps a case
   for an MTA apical plug.  Apex?  What apex?
4. A few months later, final porcelain in, fistula returns.  Go in for an
   apico- maybe not aggressive enough but I removed a ton of granulation
   tissue, scraped the area clean and packed in some DFDB.
5. A few months go by and the fistula has not been seen.  Then the fistula
   returns.  This time it has to go.  I extract the tooth and place an 11 x
   4.5 Ankylos implant and could have placed a 14 easily.  But, I did not
   have one on hand at the time of the surgery and had to get that implant
   pretty high up to get some apical engagement and stabilization.  Grafted
   defect, membrane and closed.  I used the porcelain crown as a pontic and
   temporarily bonded it to the adjacent teeth.
6. Obviously no sign of that pesky fistula now.  Implant sat for 6+
   months.  Tissue former for about 1 month.  Then placed a zircon abutment
   and empress crown.

Not a perfect case, but it turned out OK aesthetically.  My main question
is the crown to root ratio of implant length/crown and abutment length.
Would another 3 mm of implant length made a huge difference?

Comments, suggestions, questions?

Arturo



Arturo,
thanks for posting this case.
Did you finally find out, why endodontic treatment was unsuccessful? Were the root fractured?
Another point - is it just my eyes issue or the ceramic crowns have open margins?

As for your question about implant/crown ratio... I personally tend to disregard this concern if
the implant is well osseointegrated, as it seems to be in your case, so another couple of mm-s are
not that very important. Heck, try to compare root surface area of central incisor and the surface
area of 4.5x11mm Ankylos implant ;-) - Dmitri