From: John A. Khademi, DDS MS
To: ROOTS
Sent: Thursday, March 08, 2007 8:54 PM
Subject: [roots] Couple of Castings
I don't do these very often, but interestingly I had two yesterday.
This is Khademi's modification of the David Clark endo/restorative casting.
This lady saw one of the town clownicians who did this wonderful pin-retained bonded resin buildup with the crown that has margins on the restorative that fit about as well as socks on a rooster. ;-))))
Of course the pulp basically immediately died due to the bacterial onslaught, and the pin into the pulp horn probably didn't help matters. ;-))
We took everything apart, and you can see how much tooth structure was left. We did a Dovgan/Khademi Burectormy with some hard tissue removal at the lingual, and two weeks later, with instructions to brush agressively with an end-tufted toothbrush dipped in peridex, you can see the result. A flap was not reflected.
We isolated the tooth, applied a releasing agent (like vaseline--make it a thin coat, and coat the rubber dam, clamp and everything else in the field) and mixed up a really runny mix of Duralay. My litmus test of the runnyness is "Can the Duralay be sucked up through the 22g light blue UltraDent tip?" If it can, it is runny enough. David likes a smaller tip than this, but I find the smaller tips clog.
So in this ovoid case, I fit the smaller "brownish" burnout post to full length, and the red post was trimmed back to "jam in" against the brown post. Also the brown post is a bit small to use as a sprue. Fill up the post hole, and place both posts.
Build up some of the coronal portion with the Duralay. My chairside, who is in the scope with me, brings a small plastic suction over which evaporates the liquid component of the Duralay off as I place it which makes it kinda "set" or at least not run and slump. I build up enough of the coronal portion to have the Duralay well engaged to the posts. I like to wait a bit until it sets, then yank the whole thing out. In/out/in/out/in/out until it goes smoothly. Then throw it in hot water for a few seconds to set it. Then place it back in the tooth.
David builds up the whole thing in Duralay, but I like working with wax, so I marginate and build up the core portion of the pattern in wax. You can see the black wax spatula that I have used since dental school, that has been re-hired for this task. :-)))
You can see the subtle color and texture differences betwwen the radicular portion of the pattern in Duralay, and the bulk of the coronal portion in wax. To each his own.
Also of note is the marked difference in profile viewed from the B/L direction, and the M/D direction - John A Khademy
The Clark Endo/Restorative casting.
Here is the other one from yesterday. The has had this bridge with the cocci, rod and spirochete in there for a while, and yesterday was time to take things apart and put them back together.
An implant was placed in the cantilevered #6 position, and individual units are being fabricated for 7-11.
We took out the spirochete, but left the cocci and rod in place. You can see in the upside down profile pic, that there is not alot of #11 left so we made a casting.
I filled 9/10 with MTA which was surprisingly difficult even using the ultrasonic to condense. I re-packed #9 once, and #10 twice. We restored both of those teeth with Bisco DT-Lights cemented with CoreFlow.
Not wanting to prepare the buildups to fit the crowns, I removed the internal irregularities, and cut off the cantilevered portion of the bridge over the implant in the #6 position so that there was about a .5mm gap between the cantilevered pontic and the healing cap. I filled the "hole" in the pontic with flowable.
Then cemented the whole thing in place with Temp Bond.
We will have the casting shipped to her RD, who is in Telluride. He bought a Global G6 about 6mo ago, and I completely trust him to cement it.
And oh yeah, since I'm an endodontist, we did conventional retreatment endo on #11--after removing the spirochete. :-))) - John A Khademy
Was there periradicular path? - Terry
Terry, Yes on the lateral. I was able (without trying) to get past the amalgam.
I'm sure there was some occult PA path on the other two. The workup was a bit thorny and interesting, as this work has been there for some time, basically symptom free. The RD and the patient wanted to switch her to single units, and of course the implant in the #6 spot, so the restorative on each individual tooth now becomes important, vs when they are all splinted together the load is shared...
So whaddya do? Do you just jam a post down there??? :-))) The "retreatment" on the central and lateral were most interesting, as I'd swear that I was removing tartar from inside the tooth...in the canal. I am sure I did not get it all, and I spend 4hrs across 2 visits, and lots of hand files. The only rotary NiTi's I used were some bent Liberators in a low-speed latch.
What would you do? - John
We do direct castings much the same way, but instead of duralay we have switched to gc pattern resin. Much less shrinkage contraction and still burns out cleanly.
I love these posts. Socks on a rooster, pin into the pulp horn not helping, cocci, rods, spirochaetes - Gary
Actually, a liittle controlled shinkage is desirable fo rthese endo posts - Wes
I agree about the shrinkage, and I'll bet the material Gary has is just fine as well.
I just like working with wax. What happened to all the dentists who are like you? :-)))
Isn't our job to fix teeth? :-))) Gary, Thanks. Why don't you post your technique. I'd like to see it - John
Actually I haven’t done one in a while, but I do have one coming up and I’ll take some photos. Many of us in the implant world switched over to gc pattern resin a number of years ago for doing are verification stents because of the lesser degree of polymerization shrinkage. Not a major issue, but every little bit helps.
- Gary
Couple of castings
