From: Marga Ree
To: ROOTS
Sent: Tuesday, January 12, 2010 9:02 PM
Subject: [roots] Missed canal and the role of sandblasting

I have posted this case before, at least treatment at the first session, to show the benefits of sandblasting
the pulp floor to identify a canal orifice.

Patient was referred because of acute apical periodontitis, and identification of MB2 was a piece of cake.
A drop of alcohol may further enhance the visibility of its orifice.

I use my sandblaster every day, also after obturating the canals, to clean the pulp floor prior to bonding.

After the first visit, the symptoms subsided. Doing endo and a subsequent coronal seal can be so easy......
sometimes.....;-)) - Marga






Marga, "Simple" case... hmmm.... in your hands - yes!
I would have done a couple of ledges and perfs... and followed that by obturating with multiple voids :-)))

It is always a pleasure to see your cases! Thanks for sharing. - Dmitri

It just goes to show that there are typically alternate ways to do something.  I also use air abrasion on
the pulp chamber floor after obturation when placing a core.   The reason I don't use it to find canals is
primarily the mess and the fact that it scratches the microscope lens and zirconium mirrors.  Smoothing with a
fine round composite finishing bur and clearing the floor with EDTA reveals the same orifices and grooves
without making a mess....but as usual I agree with you about it being a nice final aid at the end of treatment
before core placement. -  Terry

Terry, There more ways to skin a cat. I use several tools to identify orifices.
They all have pros and cons.
1. Burs, I particularly like the Munce burs if there is quite a bit of tooth structure that needs to be removed.
   Advantage of burs is that it is a very efficient way of removing dentin or obstructions
2. US tips. Useful as well, but not very efficient. I use them when I want to smooth out an isthmus, or change
   the direction of an orifice, but you can also do that the way you described it, with a composite finishing bur.
   US tips may cause damage, e.g. chipping of porcelain
3. Air abrasion. Just to satinize the pulp floor, not to remove a bulk of tissue. Ideal for removing a minimum
   of dentin and cleaning the floor and walls in particular after obturation.
4. EDTA/alcohol, to make the color map of dentin more vivid and easier to interpret.

Marga

Yep, and cat always has sharp claws. :):):) - Terry

Terry, you wrote: the fact that it scratches the microscope lens 

Hmmm... do you have 50mm objective lens forced down directly onto the tooth? :-)) Or why particles are able to
scratch it? - they should have plenty of space to travel after bouncing off the tooth surface and magically
avoiding if not aspirator itself then at least it's tubulence ??? - Dmitri

They scratch my scratch proof lenses on my glasses and they are a long way from the tip.  Unless you swing the
scope away when using the etcher, you will eventually scratch the scope lens - Guy

All I know is that sand particles get out on stuff scratching mirrors and lens.  I doubt it's from bouncing from
tooth to lens scratching it directly, but more likely when the lens gets wiped down later with some particles
littering the area. My aspirator doesn't catch all sand particles.  You must have an amazing vacuum system. :)

I use an old mirror when I do the blasting so I don't ruin a zirconium mirror.   The beauty of composite
finishing burs is that you are sweeping away dentin as you are clearly seeing the floor anatomy.  It's more
efficient and does the same thing without making a mess of things.  I simply use the air abrasion before placement
of the core, it cleans up the floor beautifully to confirm all anatomy is taken care of and prepares the prep
for better bonding.  I'd rather make a little mess at the end rather than multiple times throughout the access
phase.  It doesn't work for me; it apparently works well for Marga and you.  It's great that Marga brought up
the idea because it is another useful way of identifying orifices and floor anatomy - Terry

Terry, I’ve got a Bulldog dry vac that will suck the chrome off of your bumper and pumice is still floating
in the room - Guy

Hi Terry, Yes, I use an old mirror as well, and my assistant holds a suction canule near the tip of the microetcher.
If you feel more comfortable, you can even push the scope away - Marga

Hi marga.  That’s exactly what I was referring to, and in fact I think I originally learned that tip from you.
and we always use it after endo obturation but before core buildup to remove all remnants of anything and provide
a clean textured surface to which to bond - gary

Nice stuff Marga! - Mark

Marga, It looks very nice, but without sandblasting I bed you would find the canal as well.
I have had a big sandblaster to bur with it, I have sold it because of all the dust in my office.
After seeing this case I will try it tomorrow - Rob

Bravo Marga....Bravo. Nice tips about the sandblaster ( I just got one - Danville ) and like it alot as well, and
the alcohol.  Thanks for sharing another gorgeous case both technically ( what else is new) and documentation wise.
-  Glenn

Very cool, Marga! :)
Now question to everyone. I have one more reendo patient with canals filled with gutta.
Yesterday I cleaned 2/3 of the canals and today I have to work with the apical parts. Just want to make sure
I use all the right ways to get gutta out, tell me plz in what way do you take gutta out of the canals in apical
part if the canals are really thin? Any tricks? - Nazariy

Chloroform, handfiles, rotaries, paper points and a lot of patience...:-) - Marga

Terry, The way I handle the concern over scratching scope lens and mirrors is to use my Danville etcher blind.
I push the scope away, I put the high volume suction over the tooth, I do direct vision with the etcher.
Then I pull the scope in and rinse the field and typically find that things worked just fine even though
I was working blind - Mark

Mark, I have a small funnel with a large tip.  I’ve cut it off so that it wedges in my evacuation.  I think it
helps when placed opposite the micro-etcher.  I had one at the office that worked like a champ and have looked
like crazy for another and cannot find one that fits as well and is as small.  It is too large to place intraorally
but it works well place opposite to the direction of the etcher tip.  I think this funnel came with a disinfection
concentrate - Guy

Yes Mark, I used to do that as well, and it works fine, although these days I don't push the scope away anymore.
I have got a plastic cover over my lens, so I am less concerned about scratching the scope lens - Marga

I have got a plastic cover over my lens, so I am less concerned about scratching the scope lens - Mark Dreyer

Don't worry about it.  Between pts have your assistant blow some dry air or use one of those computer keyboard
air cans to clean off the objective lens.  If there are any UFO's left after this use a cotton filled 2x2 with
Windex or other glass cleaner to wipe the objective lens.

I have used a scope and air abrasion (mostly for restorative dentistry and some endo) for over 10 years and have
not had any problems with the objective lens. -  Arturo