Friday, October 18, 2013

Post Removal & Endo ReTx

Today's  post is going to deal with a clinical case and a bit of technology I used to get the best result possible.  The above radiograph shows tooth #20 (FDI 35).  The patient presented with pain isolated to this tooth.  Percussion tests were positive for this tooth & no other teeth in the quadrant.  The radiograph shows a diffuse periapical radiolucency.  All radiographs for this case were taken with Gendex GXDP-700 intraoral sensors.
The challenge in this case was 2 fold.  First I didn't know what the filling material consisted of.  On occasion with endo retreats I've run into some unusual materials that are difficult to remove.  Second, and perhaps most importantly, the presence of a threaded metal post.  The removal of posts can be challenging in many cases and, unfortunately, it's difficult to tell the difficulty until you start the procedure.
I've been doing a lot of cases lately with the P5 Newton piezo unit from Acteon and not just endo either.  However, since this case deals with endo, I'll stick with that exclusively for this post (no pun intended).
The tip I chose for this case (sorry no photo) has a concave end that fits over the top of the post.  My first step here was to remove the crown using a standard "slot technique".  Once the crown was out of the way, I used an electric handpiece running very slowly with a SS White Great White cross cut bur to remove the amalgam buildup and expose the post.  With the post fully exposed and access achieved, I put the concave endo tip on top of the post and applied gentle pressure while I activated the P5 Newton unit.  Copious water spray was used to prevent overheating of the post and water removes heat 25 times faster than air.
Watching under magnification (Orascoptic 4.8x for this case although I also have an operating microscope) the post began to slowly "unscrew" from the canal.  After about 2-3 minutes of applying the tip to the post it had unthreaded to the point that it was now clearly mobile.  At that point, I engaged the post with Stieglitz forceps and unthreaded the post the rest of the way out of the tooth.
After post removal, the canal was probed with Caulk hand files to help determine the material used to obturate.  The material felt slightly tacky when probed and I proceeded to use a #2 Gates Glidden drill and noticed shavings of what appeared to be gutta percha.  I placed eucalyptus oil into the canal as a solvent to soften the material and removed the remaining gutta percha with Ultradent Tilos Niti shaping files in the Ultradent reciprocating handpiece.
Once the canal was cleaned, canal length was determined using the Sybron Endo Elements Apex Locator.  An apical stop was created and Ultradent ChlorCid V (sodium hypochlorite) was used for a 10 minute application.  The Chlorcid V was removed with a vigorous air/water rinse, the canal was vacuumed with the Ultradent  capillary tip, and then Consepsis (chlorhexidine) was scrubbed into the canal and then removed with the capillary tip.  At this point, calcium hydroxide was placed into the canal and the canal was closed.  An acrylic temporary crown was fabricated & the patient was dismissed.
At the second appointment the calcium hydroxide was removed with citric acid and a Caulk size 25 hand file in a Sybron M4 safety handpiece.
A trial cone placement was done using a Real Seal (Resilon) 30 .06 taper cone.  A cone placement radiograph was taken knowing the cone was long but that good apical tug-back was achieved.
The apical length was again gauged with the apex locator and the cone was cut at the proper apical length to ensure apical seal due to tug-back.  
The canal was vacuumed with the capillary tip, EDTA was scrubbed into the canal and vacuumed with the capillary tip.  Once the canal was dried, Consepsis was scrubbed into the canal and the capillary tip was again used, but the canal was left moist to ensure a moist bond surface.  
Obturation was accomplished for this case using the Real Seal (Resilon) cone fitted earlier and sealed using Real Seal dual cure sealer.  Warm vertical condensation and Real Seal back fill was accomplished using the Sybron Elements Obturation Unit.  Real Seal is a synthetic endodontic filing material that creates bonded obturation.   The sealer is a dual cure self etching sealer which bonds to the tooth structure and the Real Seal bonds to the sealer.  Since it is bonded obturation, every effort is made to leave the canal system moist so as to accomplish a well bonded resin system.
I was pleased with the final result and the patient reports no pain or indications of problems since the first appointment.  This was a case made much easier through the use of multiple technologies including bonded obturation.  While endodontic retreatments are never easy, the technologies employed here definitely made the case less stressful for all involved and helped to provide a good clinical result.

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